Long Beach Animal Hospital Informational Articles

Ear (aural) Hematoma

On occasion we are presented with a pet that has a swollen ear. The swelling is due to blood vessels that have ruptured inside the ear flap, between the inside and outside layer of cartilage. This causes the ear to fill up with bloody fluid and after a period of time the blood in the ear clots and there is a firm swelling. If left untreated the ear will be painful and will eventually scar down, similar in appearance to a cauliflower ear in a prized fighter that has spent a lifetime in the boxing ring.

Symptoms

The symptoms of an aural hematoma are obvious. Depending on the severity of the problem there will be swelling, which is sometimes extensive. Almost every pet will either be holding the head to one side or either shaking and pawing at the affected side.

This cat has a moderate sized hematoma.

Cause

 

Pets that paw at their ears or shake their heads vigorously, especially those with large ears, can cause a hematoma. This pawing and shaking can be due to irritants around the face and ears, or irritants in the external ear canals like infections or foreign bodies (foxtails). Food allergy is a common cause of inflamed ears, causing your pet to shake its head excessively and burst blood vessels.

 

Medical Treatment

 

In some cases we can alleviate the hematoma by removing the fluid and injecting cortisone into the ear.

This dog is having fluid drained from its ear.

Your pet will also go home with oral medication to be used for 10 days. This treatment is usually repeated in one week, although some cases are healed after the first week of therapy. Pets that don’t heal after the second treatment need surgical correction.

The initial cause of the hematoma, often times an ear infection or food allergy, will be treated simultaneously.

 

Surgical Treatment

 

We keep a close tab on important physiologic parameters for all of our surgeries. Monitors like this give us an early warning of an impending problem.

Surgery-Monitor

 

It is advantageous in most cases to use medical therapy first because there is no need for general anesthesia, there is minimal discomfort to your pet, and the cost is less than surgical correction. Surgical treatment is used in those situations in which the problem is not corrected with medical therapy.

Some hematomas are too large or involved to attempt medical treatment initially. Another reason we might perform surgical correction before attempting medical correction occurs when your pet is being anesthetized for another problem simultaneously, for example, dental disease.

The following section has pictures of an actual hematoma surgery, and includes pictures of blood and ear incisions. If you would like to pass this section up click here.

The first step in the surgical procedure is draining of the fluid in the ear. An incision is made with a scalpel blade and the bloody fluid is drained.


Since most hematomas have been present for many days prior to presentation, there are blood clots in the ear. These clots are removed with a hemostat.


When all of the blood and clots are removed the ear is ready for suturing. You can readily visualize the 2 layers of cartilage in this view.


The 2 layers of cartilage are sutured together to prevent the bloody swelling from returning. The incision is left partially open to facilitate further drainage of fluid. We also bandage the ear to the top of the head in some cases. The bandage and sutures are removed in 7-10 days. Healing progresses rapidly and the ear returns to normal in no time.

 

For well over the 15 years this  surgery is done in our hospital with the laser. Using the laser has substantial advantages over the method described above. It is highly recommended that this surgery is done with the laser, particularly because it will dramatically minimize pain during the healing process.


Once your pet has a hematoma it is possible for it to recur. You should check your pets ears daily for any recurrence, treat the initiating cause, and clean them frequently.

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Ear Infection

A common problem in dogs and cats is ear infections. A consistent cause of recurring ear infections is an underlying allergy called atopy. Another name for atopy is allergic dermatitis. Food allergies are also a cause of this recurring ear infection. Some pets have both as the cause.

There are many different causes and numerous treatment regimens to effect a cure. Since the causes tend to be multifactorial we need to address all of them for a successful outcome. Dogs tend to have more of a problem with ear infections as compared to cats.

Hygiene is of major importance both in curing the problem and prevention of recurrence. Ear infections can easily become chronic in nature, so proper therapy early in the course of the disease is important, along with long term commitment to keeping the ears clean.

Long term problems with the external ear can progress to problems with middle (otitis media) and inner (otitis interna) ears. This can cause substantial pain, equilibrium problems, and even hearing loss.

Anatomy

Dogs and cats ears differ from human ears in several significant ways. The main difference is the shape and length of the ear canal. It is longer in animals and has a downward and then inward direction. Also, their ears are more sensitive than ours. Cleaning them requires more effort than in people.

This picture shows normal dog and cat ear canal anatomy. The arrows show the downward and inward path of the external ear canal. The tip of the arrow to the left is pointing to the ear drum. When you clean the ears you will gently be pulling up on the external ear to straighten this canal out and allow deeper penetration of medication.

A normal dog ear has glands lining it they contain cilia to remove normal debris. This self cleaning mechanism works well for a healthy ear, not so well for an inflamed and infected ear. Cleaning this debris out of the ear canal is imperative for the bodies normal cleaning mechanism to work.

Symptoms

Pets commonly give their owners a clue that their ears are bothering them. Most pets will either have discharge, redness, swelling, odor, or will be shaking their head. The ears can be sensitive or painful, and your pet will be reluctant for you to pet it or touch it around the head or face. When these symptoms are present it is called otitis externa.

Sometimes the ear flap will become extremely swollen-this is called an aural hematoma. Pets that have a foreign body in their ear like a fox tail will be shaking their head extensively and frequently paw at the affected ear.

These problems might be seasonal due to allergies. In dogs there are many immunes and  inflammatory cells in the ears and skin, which is why they exhibit problems in these areas. In people these cells are in the respiratory passages, which is why humanoids get runny noses and sneezing.

Causes

Ear disease is caused by many different and predisposing factors, some of them working in combination:

Anatomy – deep ear canals, hair filled ear canals,  and long floppy ears are predisposing causes because they set up a warm and moist environment that bacteria and fungi thrive in. Cocker Spaniels, Labradors, Miniature Poodles, and Schnauzers are some of the dogs with this situation.

Breed – Some breeds like Cocker Spaniels are commonly effected because of allergies, long floppy ears, and inbreeding.

Allergy – In addition to causing itchy skin and hair loss in general, allergies can also cause ear problems. Food allergy and atopy are common causes.

Low Thyroid – On occasion low thyroid hormone can cause ear problems.

Parasites – Ear mites are also a cause of ear disease, especially in cats. Also chiggers and sometimes ticks.

Drug reactions – Any drug can cause a reaction that inflames the ear, including some cleaning agents.

Hygiene – Debris and excess hair in the ear canal can cause an infection.

Auto immune system diseases

Tumors

Sugar Diabetes

Cushing’s Disease

Feline Leukemia (FeLV) and Feline Immunodeficiency (FIV) viruses.

Canine Distemper

Bacteria – Staph, Strep, Proteus, E. coli, and especially Pseudomonas.

Excessive cleaning

Yeast – Candida and Malazzezia.

Foreign bodies – debris, hair, foxtails (plant awns).Since there are many causes to ear disease an accurate diagnosis is essential to relieving the problem.

Diagnosis

A routine physical exam is used on every pet that is presented with ear problems because ear infections can be a sign that there are problems elsewhere in the body.

This exam is an essential part of the Diagnostic Process, and might include routine blood work

Ear swabs are used to obtain a sample of discharge for microscopic analysis

Microscopic analysis of the discharge helps us determine if your pet’s problem is bacterial or fungal related. This analysis is performed in our office by taking some of the discharge from the ear canal, staining it blue with a special stain, and observing how many bacteria or fungi are noted.

A culture of the discharge from the ear is sometimes used as an aid to determine what bacteria or fungus is causing the problem. Since many organisms are usually grown in a culture, and some of them are normal inhabitants, this test is not always advantageous.

This picture shows a culture that grew out a staph infection and a fungal infection called Malassezia

The otoscope is an important tool that allows us to visualize the anatomy of the external ear canal, including the ear drum. It is also used to retrieve foreign bodies, usually foxtails, from the ear canal, and to check for tumors. Ear infections are painful, and some pets need to be sedated before they let us examine their ears.

There are different sized cones depending on the size of the ear canal. The cone in this picture is one of our smaller ones. 

Checking for proper thyroid level is an important test in every dog that has recurring problems, especially in Golden Retrievers. This is a report from a pet that has a low thyroid level.

In addition to these tests, allergy tests are utilized when they are suspected as the cause of the problem. A blood sample is taken that tests for allergies to food, commonly found material inside of your house, and plant like materials found throughout our area in the outdoors. Your doctor will let you know if this test is needed.

Treatment

Each ear infection requires specific treatment depending on the results of the physical exam and diagnostic tests. If there are underlying problems your doctor will prescribe medication to prevent them. In the overwhelming majority of cases medical care is all that is needed. Surgical correction of an ear infection is usually used only after medical care has been unable to control the problem.

If your pet has recurring ear problems we need to control the allergy that is likely causing this. If it is atopy, there are many things we can do to either prevent exposure to the allergen causing the problem. Food allergy is a common cause of recurring ear infection, so a trial of Hill’s Z/D or D/D will be indicated. Our Allergic Dermatitis page has all the details.

For the majority of ear infections proper cleaning and routine topical medication will correct the problem. Learning how to clean your pet’s ears is crucial. Once you have an ear infection under control, which takes 3-7 days in most cases, your goal should be to clean your pet’s ears once or twice each week in order to prevent recurrence. Infections that continually recur are very painful and substantially decrease your pet’s quality of life.

In many mild cases we are able to clean the ears in our office without sedation. After we perform the initial cleaning in our office your job at home will be much easier. You will need to clean them at home to effect a cure and prevent recurrence. You do not clean them if our doctor is using Osurnia. Our nurses will demonstrate exactly how to do this with your pet. To learn the technique click here.

For pet’s with ears that painful to clean we will anesthetize them and thoroughly, yet gently, flush the debris out and instill medication. This is a huge start in your hygiene protocol at home.

Your doctor will routinely prescribe two medications. The first is used to gently clean the ear canal and remove debris and infection. The second medication is a combination preparation that kills either bacteria, fungi, or parasites. These medications usually contain an anti-inflammatory preparation to soothe the ear also. Occasionally your doctor will prescribe oral medication to clear up the infection and to decrease the inflammation in the ear canal.

Topical medications like this one are routinely used to treat. They have medication to treat bacteria and fungi, and also to decrease inflammation.

This is another topical medication that is used, especially for resistant bacteria

There is even a gel that is placed in the ear canal that lasts up to 45 days for pets that are difficult to medicate

Once we clean the ears we place this medication in the ear using the premeasured single-dose tube.  It contains three ingredients that are beneficial to clear up the infection, both bacterial and fungal,  and also sooth the ear. That is all you have to do for one week. In one week we recheck the ear to make sure the infection is getting under control, then we place another tube of medication in the ear. If your pet has no underlying problems as described above the infection is usually cleared up, and you don’t need to clean and medicate the ears daily. The ears are not cleaned again until 45 days have passed.

Many dogs have excessive hair inside of the ear canal. If this hair is causing a problem it is removed to facilitate cleaning and to let air circulate into the ear canal. This should be done routinely, which for most dogs is at least once monthly. If you or your groomer are reluctant to remove this hair, we will do it for you.

These ears are typical of a pet that needs the hair removed from its ears and a thorough cleaning. Sometimes just removing the hair from the ear canals completely corrects any problem, so please keep them hair free at all times.

These are the same ears after one of our nurses has cleaned them. It is obvious from the picture that this pet will feel much better from this treatment. It is a common-sense approach, and does not require any medication.

The dirty ears on this cat predispose it to an ear infection

It’s hard to believe these clean ears are from the same cat. 

In some pets the ears are so inflamed that its painful to clean the ears. In these severe cases we use sedation and flushing. A warm cleansing solution is used to remove debris and infection from deep within the ear canal by flushing action only. These ears are painful and we need to go gently so as not to cause more pain and damage to an already severely inflamed ear canal.

A soft and flexible tube, with a warm cleansing solution, is used. 

This ear has had recurring infections for so long that it is no longer possible to clean the external ear canal. The canal is swollen shut, infected and very painful. The only adequate remedy in this case is surgical correction to completely remove the ear canal. This surgery is called a total ear canal ablation. This surgery requires a surgeon with specialized training and expertise. The goal of long term ear care is to never let the disease progress to this point.

 

The ear canal is swollen shut, and cannot be cleaned. Surgery is the only option, and it works very well. Your dog will feel dramatically better after this procedure, although it will not be able to hear any sounds out of this ear. 

Here is another dog with the same problem as it is prepped just prior to surgery for correction of the problem. 

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Hip Dysplasia

Hip dysplasia is a congenital disease that affects mostly large breed dogs, although any breed can get it, and even cats can have a problem with their hip sockets.

Hip dysplasia is a laxity in the socked of the hip joint where the head of the femur fits into the pelvis. It causes weakness and lameness to the rear quarters, and eventually leads to painful arthritis. This arthritis goes by several names; degenerative joint disease, arthrosis, osteoarthritis.

This disease is so prevalent, and so debilitating, that a special veterinary organization called The Orthopedic Foundation for Animals (OFA) was organized to minimize the problem in the breeding pool of dogs. It occurs rarely in cats, primarily the Maine coon, and usually in females.


Cause

Many factors work together to cause this disease, which is a combination of a dog genetically inclined to get this disease interacting with environmental factors that bring about the symptoms. These environmental factors excess calcium in the diet of puppy food for large breed dogs, along with obesity, high protein and calorie diets, and a lack of or too much exercise. The breeding of dogs that already have hip dysplasia is one of the primary reasons the disease is still present. A dog that has hip dysplasia in one socket is prone to having a problem with the ligaments of the knee in the other leg (anterior cruciate rupture).

Pathophysiology

During the degenerative process the cartilage that lines the hip joint, called hyaline cartilage, is damaged. The damage results from the abnormal forces on the cartilage from the deformed hip socket. Small fractures can occur in the cartilage also. Eventually an enzyme is released that degrades the joint further and decrease the synthesis of an important joint protectant called proteoglycans. The cartilage becomes thinner and stiffer, further compromising its ability to handle the stresses of daily movement and weight bearing.As the problem progresses more enzymes are released, which now affect the precursors to proteoglycans, molecules called glycosaminoglycans and hyaluronate. Lubrication is negligible, inflammation occurs, and the joint fluid can no longer nourish the hyaline cartilage. This viscious cycle continues until pain occurs. The body attempts to reduce this pain by stabilizing the hip joint. New bone is deposited at the joint, both inside and out, along with some of the ligaments and muscle attachments to the area. This causes thickening and a decrease in the range of motion. This is the actual arthritis noted on a radiograph, which will not go away, and will continue to progress.

 

Breed Predispositions

Many dogs can develop hip dysplasia. Dogs that were commonly affected years ago, like German Shepherds and Labrador Retrievers, still get the disease but not as commonly as before.

According to the OFA some of the breeds with the highest prevalence are:

Bulldog Pug Otterhund Clumber Spaniel
Neapolitan Mastiff St. Bernard Boykin Spaniel Sussex Spaniel
American Bulldog Newfoundland American Staffordshire Terrier Bloodhound
Bullmastiff Chesapeake Bay Retriever Golden Retriever Gordon Setter
Rottweiler Chow Chow Old English Sheepdog Kuvasz
Norweigan Elkhound Giant Schnauzer German Shepherd Bernese Mountain Dog
English Setter Black and Tan Coonhound Shih Tzu Staffordshire Terrier
Welsh Corgi Beagle Briard Brittany
Bouvier des flandres Welsh Springer Spaniel Curly Coated Retriever Polish Lowland Sheepdog
Portugese Water Dog English Springer Spaniel Pudel Pointer Irish Water Spaniel

Diagnosis

Hip Dysplasia is diagnosed based on a history of weakness or lameness to the rear legs, especially after exercise or when first getting up after resting. Some young dogs will bunny hop when running, and might lie down on their stomachs with their legs stretched behind them. It is possible to palpate joint laxity on some dogs that are anesthetized (we call this the Ortolani sign). Sometimes we will feel grinding, called crepitus, in the hip joint as we move the leg around the socket.

Many variables affect the degree of lameness. They include age of onset, caloric intake, degree of exercise, and weather. To further add to the complication, pets with terrible looking hips on radiographs might act as if nothing is wrong, while others with barely discernible changes on their radiographs might be severely lame.

Radiography

Radiography (X-ray) is the definitive way this disease is diagnosed. It is not perfect though, since a dog can be hip dysplasia free on the radiograph (phenotype), but can be genetically predisposed to the disease (genotype). These dogs have the potential to be carriers of the disease, yet show no symptoms themselves.

In order to make a diagnosis, the pelvis must be aligned, and the legs extended. This can only be done when a dog or cat is under sedation. We take two views of the pelvis:

  1. VD (ventro-dorsal)- In this view your dog is on its back when we take the radiograph of the pelvis
  2. 2.Lateral- In this view your dog is on its side

Your dog needs to be mature to be able to diagnose hip dysplasia accurately. If it is too young the growth plates are not fully formed.

Pup-growth-plates-hip-radiograph-pelviis-vd

These are the pelvic radiographs of a 3 month old pup

Pelvis-growth-plates-dog-canine-VD

At 6 months of age you can still see the growth plates, and it is still too early to make a diagnosis

Normal-hipsweb

The pelvis radiographs of a mature dog with normal hips

Pelvis-lateral-radiograph-xray-dog-hip-dysplasia

You need to look at the pelvis in two views to make a proper diagnosis- this is the lateral view 

These are the x-rays of a dog with a normal pelvis. The diagram below explains why these hips are normal. 

On the right side of this normal pelvis we have outlined 2 important anatomical features. The “U” shaped appearance of the neck (outlined in white), and the full rounded appearance of the head (outlined in black), are normal. They indicate a full socket with a tight fit and no signs of secondary changes due to instability of the ball and socket joint.

Here is a larger view of normal hips with digital radiography you can click on to see more detail

Canine-Hip-Dysplasia-pelvis-VD-Gereman-Shepherd

This dog has moderate changes that indicate it has hip dysplasia on both sides. The sockets are not as rounded as they should be, and the head of the femurs are slightly flattened. 

BadHipsarrowsweb

This dog has mild hip dysplasia radiographically. The arrows point to boney projections from the pelvis. This is painful secondary arthritis forming due to the instability of the hip socket.

This is a case of severe hip dysplasia. The arrows point to the thickened femoral neck on each side along with the secondary arthritis occurring on the left side. Notice how flat the sockets are and the lack of rounded appearance of the femoral head. This dog is probably in pain and has a difficult time walking in the rear quarters.

If left untreated the disease continues to progress, eventually causing a crippling lameness and severe pain. Correcting this problem at an early age might have prevented this.

SevereHipDysplasia

This is a another digital radiograph of even more advanced secondary arthritis in a dog with severe hip dysplasia

Dogs are not the only species that gets hip dysplasia. It can also occur in cats (Maine Coons are commonly affected), although not as common as in dogs.

The white arrows outline the large amount of stool in the colon of the above cat with feline hip dysplasia. It is painful for this cat to squat to have a bowel movement, as a result it gets severely constipated.

Other diseases that cause lameness or soreness in the rear legs can mimic hip dysplasia. These include rupture of the cranial cruciate ligament in the knee, panosteitis, and degenerative disease of the spinal cord called degenerative myelopathy, a disease that occurs in German ShepherdsIntravertebral disk disease (IVD) can also cause similar symptoms.

Medical Treatment

Medical therapy might help in some cases. It depends on the size of your dog, what its function will be in your household, age, and severity of the problem. You might need to try several treatments until you find the one what works. Many of these treatments need to be used in combination with other medical therapies. Please keep in mind that large breed dogs are stoic. Do to their propensity to please you, these dogs can see fine on the outside but are painful on the inside. Watching for subtle signs is important.

Medical therapy will not cure the problem, and in most cases painful arthritis will set in. Early surgical intervention is usually the best course of action. It is not uncommon to radiograph your dog’s pelvis when it is already under anesthesia for a spay (OVH or ovariohysterectomy) or neuter.

Environmental

Keeping your dog’s weight under control and providing controlled exercise are very beneficial. Going for short walks will give you an idea of your dog’s limits. Proper exercise will maintain muscle tone and keep the joints moving and more fluid. Provide a warm environment and a well padded bedding area are also of benefit. Additional warmth helps chronically infected joints. Hot water bottles are helpful. We don’t recommend electric heating pads because of serious burn potential.

Swimming in a pool if your dog is comfortable with it can be beneficial. Hydrotherapy in a tub supervised by a veterinary certified in rehabilitative medicine is also helpful.

Non-Drug

Acupuncture, Laser Therapy, and VNA are excellent treatment choices in many cases because they are effective without the use of drugs. Our  Alternative Medicine page has detailed information.

Gentle passive range of motion exercises might help. Use of the food J/D (joint diet) is also recommended. There is also a version of J/D called Metabolic and Mobility that decreases weight in obese dogs while also providing treatment for the arthritis. It contains extra amounts of omega-3 fatty acids which might help reduce joint inflammation. One of these foods should initially be tried on all dogs with hip dysplasia.

Drugs

Many drugs have been used to control the pain associated with the secondary arthritis that occurs with hip dysplasia. Some of these drugs are extremely effective, and can provide a dog with a high degree of relief from pain. They only mask symptoms though and do not cure the problem.

Buffered aspirin and ascriptin (aspirin with maalox) are readily available over the counter remedies. Tylenol should not be used in dogs because of its potential for side effects. Tylenol is NEVER used in cats because it can cause a serious disease called methemoglobinemia.

NSAID’s (Non Steroidal Anti-inflammatory Drugs) are highly effective prescription medications. The work by inhibiting the release of prostaglandins, leading to less inflammation in the joints. They should be given prior to any bout of exercise. Some dogs will vomit or have diarrhea on these medications. Giving the medication on a full stomach and using GI protectants like Pepcid AC can minimize this problem. Their  use in labradors should be carefully monitored for signs of liver problems. Any dog that is on these drugs long term should have a blood panel taken to monitor internal organ function, especially kidney and liver.

Nutraceuticals are popular arthritis treatments, primarily because they are thought of as more natural than drugs. Humanoids use them commonly. They provide the raw material that enhance they synthesis of glycosaminoglycan and hyaluronate. Controlled studies are lacking to determine their true effectiveness. Oral versions take at least one month to become effective. A great advantage is their lack of side effects. Oral versions include Cosequin, Synovicare, Glycoflex, arthramine, and MaxFlex. Injectable versions include adequan, a drug that has been used in veterinary medicine, especially in horses, for many years. Injectable versions achieve a more rapid response than oral medications.

An injection of a drug called Adequan is helpful in many cases. This is an FDA-approved disease modifying drug. It contains a polysulfated glycosaminoglycan that inhibits the enzymes in the joints that cause inflammation. It is given as an injection, up two twice per week, and stopped after 8 treatments.

We can’t predict which medications will work best in an individual case. Trying different ones, even using some of them in combination, can let you determine which is the best approach in your dog.

Surgical Treatment

Most cases of hip dysplasia, especially in younger dogs, are treated surgically. One of the surgical specialists we consult with will make the determination of which procedure is the most appropriate. Three main types of surgery are performed:

  1. Femoral Head Ostectomy (FHO) or Excision Arthroplasty
  2. Triple Pelvic Osteotomy (TPO)
  3. Total Hip Replacement (THR)

This area contains graphic pictures of actual surgical procedures performed at the hospital.

1. Femoral Head Ostectomy (FHO) or Excision Arthroplasty

In this procedure the head (or ball) of the femur is removed. The remaining part of the femur forms a false joint with the muscles, ligaments, and tendons in the area. Even though this false joint is not as good as a real joint, there is a significant reduction in pain. almost any sized dog can have this procedure even though it is much more effective in smaller dogs. Obese dogs and those with significant loss of muscle do not do as well. Compared to the other types of surgery this one is much more basic, yet many pets that have this surgery return to almost normal function.

This are the hips of Mickey, a very active australian Shepherd. He has hip dysplasia on both sides. FHO surgery will be performed on his right hip.

After the skin incision is made the muscles are separated to give visualization of the femoral head. It is gently rotated and brought up as far as possible.

A special air powered drill is used to cut the neck of the femur at just the right angle.

The angle in the cut of the femoral neck is apparent. also present on the head of this femur is a piece of the round ligament, one of the structures that anchors the head of the femur into the socket.

An opening remains where the head of the femur used to reside. The remaining bone will form a false joint, and return this pet to almost 100% function.

The muscles that were separated and cut are now carefully sutured. These muscles are necessary for normal movement of the false joint that will soon form.

This is what remains after the surgery. Mickey healed rapidly after the surgery and is running around as fast as before, according to his worried mom.

We also do the FHO procedure when there is a fracture at the neck of the femur. This link has detailed pictures of the surgery. Click on the photo below to see how we did an FHO surgery on this dog with a fractured pelvis and neck of the femur.

2. Triple Pelvic Osteotomy (TPO)

This surgery is used in large breed dogs no older than 10 months of age. Candidates for this surgery can only have mild hip dysplasia and no signs of secondary arthritis. During the procedure the pelvis is cut and rotated slightly so that the head of the femur has a tighter fit into the socket. Since the pelvis is being cut it needs to be stabilized with bone plates.

The pelvis is cut in 3 locations. The locations of these cuts allows the proper rotation of the hips.

This is the final result after a TPO surgery. These two plates are angled to provide the proper pelvic rotation.

Click on this radiograph for a larger view of a TPO surgery

tpo

3. Total Hip Replacement (THR)

In this procedure the neck and head of the femur are replaced with stainless steel or titanium implants. This is a highly specialized procedure performed only by select veterinarians. It is used in young dogs that have achieved most of their skeletal growth and in adult dogs that weigh at least 40 pounds. It can be used in dogs that already have secondary arthritis, unlike the TPO. It has a high success rate but has to be performed carefully because if post operative complications occur they can be difficult to control.

This is the end result of the surgery. These implants now make up the ball and socket joint, and will remain fully functional for many years.

An additional treatment modality that has yielded great success in treating hip dysplasia is called VNA. It is a non-invasive and non-painful way to stimulate the nervous system to help the hip dysplasia syndrome.

Prevention

This is achieved by neutering pets that have the disease. Dogs can be screened for this problem by taking radiographs of their hips at 2 years of age. If they are certified free of hip dysplasia by the Orthopedic Foundation of america (OFA), there is much less of a chance they will sire offspring with the problem. It is best to purchase large breed dogs only if their parents are OFA certified to be hip dysplasia free.

No guarantee can be given when breeding hip dysplasia free dogs radiographically that their offspring will not deveop the disease. A dog can be hip dysplasia free on a radiograph, yet still carry the genetic predisposition to this disease that will be transmitted to its offspring.

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Spleen Disease (Hemangiosarcoma, Hematoma)

It is not uncommon for us to encounter problems with the spleen. Sometimes it just enlarges without any major problems, sometimes it twists on itself, sometimes it causes internal bleeding, and oftentimes it becomes cancerous. This page will emphasize cancer of the spleen, called hemangiosarcoma..

In breeds that have a high incidence of splenic tumor we recommend yearly exams starting at 5 years of age,  with radiographs and ultrasounds to catch this problem early before complications and spread, since the prognosis is poor in most cancerous spleens because they have already spread by the time of diagnosis.

Unfortunately, some pets, especially large breed dogs, will not show any symptoms until the spleen is huge. This occurred with a Labrador Retriever that was presented to us with the owner telling us “he just wasn’t doing right”.  He was eating good, was not vomiting, had no diarrhea, and was not coughing. This owner was astute and brought him in for an exam just in case.

A thorough exam and blood panel revealed no problems, so a radiograph was taken. This radiograph revealed a large abdominal mass. This could have been coming from the liver, spleen, intestines, kidneys, pancreas, or mesenteric lymph nodes. An ultrasound revealed it was from the spleen. The next day we removed an 8 pound rupturing spleen! You can see pictures of the surgery to remove this large mass in the surgery section later in this page, along with pictures of a dog with an even larger spleen!

Graphic surgical photos are on this page, especially of surgery which tends to be bloody.

Nomenclature

We will use some medical terms regarding the spleen:

  • Extra medullary hematopoeisis- The making of red blood cells outside of the bone marrow
  • Reticuloendothelial system- in regards to the spleen, it is the system that recycles red blood cells
  • Anemia- a low amount of red blood cells or hemoglobin
  • Thrombocytopenia- a decrease in thrombocytes, which are an important part of the clotting factors when there is bleeding.
  • Hemoabdomen- free blood in the abdomen
  • Splenomegaly- enlargement of the spleen as a result of any cause
  • Splenectomy- removal of the spleen
  • Hypersplenism- an enlarged spleen that is normal and not causing any problem

Spleen Anatomy

The spleen is an elongated and relatively flat organ that resides in the abdomen of mammals along the outer edge of the stomach. It has a tremendous blood supply that is closely attached to the blood supply supporting the stomach. It is the largest filter of blood in the body.

It has an outer capsule composed of smooth muscle and elastic fibers. The internal part of the spleen (called the parenchyma) has white pulp and red pulp. The white pulp is lymphatic tissue and the red pulp is part of the venous blood system. In between these pulps is elastic tissue that can fill up as needed.

A normal spleen in a cat

A normal spleen in a  small dog

A normal spleen in a medium sized dog

A swollen spleen in a medium sized dog

The blood supply to the spleen is closely adjoined to the stomach. You can see the dark vertical blood vessels in this photo as they enter fat between the stomach and a very enlarged and dark spleen in a semi-circle at the far right.

Physiology

The spleen has many functions. The four primary ones are:

  • Storage of cells
  • Production of red blood cells
  • Filtration of the bloodstream
  • Production of cells for the immune system

Iron that has been recycled from old red blood cells is stored in the spleen where it awaits transport to the bone marrow.

Fortunately, the body can get by without a spleen in most cases, so if there is a serious problem, and all other factors are equal, we will remove it. We tend to remove only spleens that are cancerous, rupturing, or have a torsion.

Diseases

Splenomegaly

Splenomegaly is a generalized term that simply means enlargement of the spleen. In some species, like ferrets, an enlarged spleen can be normal, and is called hypersplenism. A spleen can be enlarged diffusely or it might  have nodules in certain areas.

There are many causes for an enlarged spleen. The most common and important are listed in more detail below. Some of the more uncommon ones are due to infectious agents (erlichiosis, babesia, hemobartonella), FIP, medications, and immune mediated diseases.

This spleen has splenomegaly in addition to numerous nodules

Splenic Torsion

In this problem the spleen twists on itself, compromising the blood supply. When the spleen twists the blood keeps on pumping into it by the arterial system, but this same blood is not able to leave through the venous system, and the spleen becomes grossly engorged.

It can occur on its own, after excessive exercise, or due to trauma. It can occur in conjunction with Gastric Dilatation Volvulus (GDV), also known as bloat. We tend to see this torsion, along with GDV, in large and deep chested breeds.

If the torsion is chronic, there might be no symptoms at all, or there might be:

    • poor appetite (anorexia)
    • weight loss
    • discolored urine
    • vomiting- might be intermittent
    • weakness
    • weight loss.
    • collapse
    • death

Examination of a pet with splenic torsion might reveal:

    • pale mucous membranes (gums)
    • rapid heart rate (tachycardia)
    • painful abdomen
    • a large mass in the abdomen upon palpation
    • fever
    • dehydration
    • jaundice (icterus)

Icterus, also known as jaundice, is a yellow discoloration

icterusgums

A blood panel might reveal:

    • anemia
    • low platelets (thrombocytopenia)
    • elevated white blood cells (leukocytosis),
    • elevated liver enzyme tests,
    • hemoglobin in the urine (hemoglobinuria)

This disease is diagnosed by imaging tests when the above symptoms are present. A radiograph might reveal a mass in the abdomen with the spleen abnormally located. Ultrasound can confirm the problem and give us an idea of its severity.

A splenic torsion is considered an emergency, so the treatment of choice is surgical removal after a pet has been stabilized by treating for shock. On the deep chested breeds we might even tack the stomach to the abdomen to help prevent potential GDV in the future.

Splenic Cancer

Some splenic masses that are cancerous are classified as benign, meaning they do not generally spread (metastasize), and only take up extra space within the abdomen. Even though they do not spread, sometimes this extra space they take up can interfere with other organs.

Some benign cancerous masses include lipoma (fatty tumors), hemagioma (associated with vasculature), and plasmacytosis (infiltration of plasma cells throughout the splenic nodule or tissue in general). Unfortunately, when a spleen has cancer it commonly is the malignant version and not this benign version.

 The most common malignant tumor in the spleen is the hemangiosarcoma (HSA). It is also called malignant hemangioendothelioma). The cause is not known. It can spread to many different organs, making it highly malignant:

      • heart
      • lungs
      • muscle
      • skin
      • bones
      • abdomen
      • diaphragm
      • brain
      • kidney

HSA can also cause complications, such as disruption of the coagulation cascade which causes a mixture of abnormal clot formation as well as inability to control internal bleeding (known as disseminated intravascular coagulation, DIC).

Symptoms of HSA vary, and range from mild to severe. In extreme cases sudden blood loss can lead to sudden death.

These large nodules on this spleen are a malignant cancer called hemangiosarcoma

Another common type of malignant splenic cancer is lymphosarcoma, a type of cancer that can have a primary tumor in any other organ (i.e. lung, gastrointestinal tract, liver). Lymphosarcoma is one of the more common tumor types observed in the spleen of cats. Sometimes the tumor within the spleen is not even the primary tumor, but rather a single nodule or multiple nodules due to metastasis from a distant primary tumor.

Hematoma

Hematomas are one of the most common causes of an enlarged spleen in dogs, representing over 50% of splenomegaly cases. This type of splenic mass is basically an accumulation of pooled blood within the splenic tissue; many stop growing and are then resorbed after a period of time, but others grow exponentially and eventually rupture. A ruptured hematoma originating from the spleen is an emergency, and often the pet experiences an acute collapsing episode followed by a significant loss of blood into the abdomen (hemoabdomen). You can see the surgery of a dog with an 8 pound hematoma later in this page

Other causes

Congestions of the spleen can occur from iatrogenic causes, which are those associated with administration of certain drugs (i.e. anesthetic agents or tranquilizers). Congestion can also occur due to increased blood pressure within the vasculature of the liver (known as portal hypertension), which can occur secondary to congestive heat failure among others.  The spleen can over-react to particular conditions, resulting in a disease process known as hyperplastic, or reactive, splenomegaly. A spleen can become reactive when there is excessive stimulation of the immune system from conditions such as immune-mediated disease, bacterial infections, tick-borne diseases, and many more.

This spleen has a laceration

Diagnosis

Signalment

Dogs, cats, and ferrets can get splenic diseases, although it is much more of a problem in dogs. Splenomegaly itself can occur in most any age due to the numerous causes of the condition. For instance, if the cause of splenic enlargement is infectious, then the pet may be quite young. However, if the enlargement is cancerous, the pet tends to be middle aged (average 10 years in dogs). Due to the wide range of causes, there is no known gender predilection (males tend to be affected equally as often as females). Certain disease processes tend to be over-represented by specific breeds:

Splenic torsion tends to occur in large breed, deep-chested dogs:

Splenic tumors like HSA tend to occur in several breeds. It can be some common in some breeds that we  recommend physical exams, blood work, abdominal radiographs, and especially abdominal ultrasounds, yearly in these dogs as they reach 5 years of age:

    • German Shepherds
    • Golden Retrievers
    • Portugese Water Dogs
    • Boxers
    • English setters
    • English pointers
    • Great Danes
    • Skye Terriers
    • Bernese Mountain Dogs

History

In many cases, a patient with splenic disease has very little or no specific clinical signs. Observations made by owners at home might include non-specific indicators of illness:

    • lethargy
    • inappetence
    • weight loss
    • diarrhea
    • vomiting
    • collapse
    • discolored urine
    • abdominal distention

Physical Exam

Upon palpation of the abdomen, significant abnormalities of the spleen can usually be detected, especially when a large mass is present within the cranial aspect of the abdomen (toward the chest). However, a mass or enlarged organ in the cranial abdomen cannot always be differentiated from a mass or enlargement of the liver. In some cases, decreased pallor (pale gums) can be a sign of anemia or shock, which in combination with an abdominal mass can indicate a ruptured splenic mass or torsion. We confirm this with an ultrasound before surgery.

If the gums are pale, certain diseases of the spleen may lead to free blood in the abdomen, which can sometimes but not always be detected by palpation of a fluid wave. Other generalized signs might include weakness, fever, dehydration, poor pulses, increased heart rate (tachycardia), increased bleeding at site of blood draw (due to coagulopathy), and/or increased size of peripheral lymph nodes.

Diagnostic Tests

Some diagnostic tests which provide significant information include radiographs, blood work, ultrasonography, evaluation of the cells (cytology) through a fine-needle aspirate sample, and surgical exploration.

Radiography

The arrow points to what a spleen looks like on a radiograph. It is enlarged, although a lobe of the liver can easily overlap the spleen and make the spleen look enlarged. So in this case, technically its called hepatosplenomegaly.

Here is a dog with an enlarged spleen. Can you see it?

Splenectomy -SpleenRadSplenectomy -SpleenRadSplenectomy-LateralRad

The red circle delineates the enlarged spleen.

L.I. – Large Intestine

Pr- Prostate

Splenectomy -SpleenRad Splenectomy-SpleenRadCircle

Blood Panel

Blood work (clinical chemistry and complete blood counts) is a crucial component for detection of compromised organ function. Splenic involvement might reveal anemia (decreased red blood cells), thrombocytopenia (decreased platelets for clotting), leukopenia (decreased white blood cells) and reticulocytosis (increased immature red blood cells to indicate that the body is trying to compensate for the loss of mature red blood cells).

This is a blood panel that might be seen with splenic disease, although many other diseases can also cause this type of blood panel. The primary problem in this blood panel is anemia.

Fluid Analysis

If abdominal fluid is present we can remove it and analyze it. This is called abdominocentesis. There is no guarantee this will make a diagnosis since many cancers, including HSA, might not be found in this fluid.

Ultrasonography

Ultrasonography has revolutionized diagnosis in animals, and prevented many unnecessary exploratory surgeries (called celiotomies or laparotomies), while at the same time alerted us to the fact that we need to do immediate surgery. Keep in mind, our patients do not talk to us, and  an enlarging tumor in the abdomen in one of us humanoids would be uncomfortable, and cause us to seek medical care long before we see a dog or cat with a tumor growing in the abdomen.

Ultrasonography of the abdomen is an important modality for diagnosis of splenic disease because of its sensitivity to changes of organ size, shape, location, and even texture. An ultrasonographic examination in combination with radiographs provides a comprehensive understanding of which organs are involved and often helps to narrow the possibilities down to a select few differentials.

We use ultrasound to confirm our suspicions of a splenic tumor based on the breed, history, exam findings, and blood panels and radiographs. Ultrasound confirms the diagnosis, lets us know if the spleen is already rupturing, tells us the size of the spleen, and if there are any other internal organ problems. A critical component of the ultrasonographic exam in HSA is echocardiography (evaluation of the heart). A key site of metastasis associated with hemangiosarcoma is the right atrium. HSA that has spread to the right atrium of the heart is a serious sign, and the prognosis is not good. This is important information if we are thinking of surgical removal of the spleen.

The lines demarcate the margins of this spleen

Do you see the spleen in this picture without the demarcation?

A typical ultrasound report on a dog with a cancerous spleen

This ultrasound of the heart (echocardiogram) shows spread of the tumor to the right atrium, which is a poor prognosis

RV- Right ventricle

RA- Right atrium

Cytology

Aspiration of the cells in an organ for cytological exam by a pathologist is an important part of most abdominal ultrasounds. It helps prevent an exploratory surgery, and can lead to a diagnosis in many cases. Cytologic evaluation of splenic problems is not always indicated and can sometimes be contraindicated depending on certain disease processes. Certain cancers of the spleen as well as hematomas may result in significant blood loss if stuck with a needle due their fragile nature. Even though the ultrasound guides the biopsy location, if the disease process only involves a small portion of the splenic tissue, or is sporadically located throughout, then a small needle-sized sample may not obtain the affected tissue at all.

ECG (Electrocardiogram)

This tests the electrical activity of the heart. I some HSA’s there will be an arrhythmia

Definitive Diagnosis

Histopathology is the analysis of the spleen after it is removed. This gives us our final diagnosis.

Histopathology

Treatment

Surgery is a common treatment for splenic disease. This is called a splenectomy. If there is trauma or a problem in only a small part of the spleen, we might do a partial splenectomy since we always want to preserve as much function of the spleen as possible. This partial splenectomy is not common.

We do the surgery to remove the tumor, and if malignant add chemotherapy to help prevent spread after we do the surgery. Prior to surgery we do an ultrasound of the heart as already mentioned, and also take chest radiographs to check for spread of a tumor. We also perform a clotting panel since blood loss is common in this surgery and we do not want post operative bleeding.

Unfortunately, survival time for dogs and cats with surgery alonge HSA is only 1-3 months, with most dogs dying due to spread of the HSA to other organs, causing these organs to malfunction. This emphasizes the need for an early diagnosis in the breeds prone to this cancer.

Dogs that have surgery to remove the spleen, and that are also treated with chemotherapy, might survive up to 9 months. This depends on whether the tumor has spread, and again emphasizes the need for an early diagnosis. Dogs and cats have less side effects than people on chemotherapy, and their quality of life is high if this therapy is instituted immediately after surgery.

Dogs that are diagnosed at a young age, have had the HSA rupture prior to surgery, have evidence of spread to other organs when the splenectomy is performed, or have a more aggressive grade of tumor, do not tend to live 9 months after surgery.

The primary chemotherapy drug for HSA is Adriamycin (doxorubicin). It will slow the disease process, but it will not cure your pet of this disease. The doctors at the Veterinary Cancer Group in Tustin institute this therapy.

If a pet is anemic, or we anticipate significant blood loss during surgery, we will give a blood transfusion prior to surgery or during the procedure. Post operatively if a pet is not doing well we will give a blood transfusion also.

After doing a cross match to ensure compatibility we obtain whole blood for the transfusion

Splenectomy

A splenectomy is performed to treat and sometimes cure this problem. It is sometimes done as an emergency procedure if the spleen has ruptured and there is significant internal bleeding.

Pre-anesthetic preparation is important in every surgery we perform, no matter how routine, because surgery is not an area to cut corners.  Once a pet is anesthetized, prepared for surgery, and had its monitoring equipment hooked up and reading accurately, the surgery can begin.

This is a sterile abdominal surgery, and our surgeons scrubs with a special antiseptic soap prior to gowning and gloving

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While our patient is being anesthetized our surgeon is already in our surgical suite setting up instruments. Our surgeon is ready to start before our patient is at a proper plane of anesthesia. Once the anesthetist gives the green light the surgery starts immediately. We want our surgeon waiting for his patient, not the other way around.  All of this is to minimize anesthetic time.

OVH-rabbit-3

OVH-rabbit-2

We keep a close tab on important physiologic parameters for all of our surgeries. Monitors like this give us an early warning of an impending problem.

This machine monitors:

Temperature

Heart Rate

Heart rhythm

Oxygen saturation

Carbon dioxide level

Respiratory rate

Surgery-Monitor

In addition to our monitoring equipment our anesthetist stays “hands on” in monitoring important physiologic parameters. In addition to our monitoring equipment our anesthetist stays “hands on” in monitoring important physiologic parameters. Our anesthetist is using a special stethoscope (esophageal), that is passed down the esophagus and lays right over the heart. This gives us a clear sound of the heart and how it is beating.

Rabbit-femurfx-9

To minimize anesthetic time we routinely have 2 doctors working as a team performing the splenectomy.  They work together as a well orchestrated team.Our patient is under anesthesia and our surgeons are completing the draping process while our anesthetist is adjusting the surgical lights.

By working together early in the surgery we minimize anesthetic time.

For a pet that might already be anemic it is important to minimize blood loss during surgery. Special care is taken on entering the abdomen to minimize loss. There is minimal bleeding at this point as our surgeon gently dissects the sub Q (subcutaneous) tissue just under the skin.

As the surgery progresses we sometimes encounter significant bleeding from blood vessels in the sub Q fat and from muscles that are cut. All of them are clamped or cauterized before proceeding further. For a pet that might already be anemic this added blood loss is important to control, and it is stopped immediately.

When all bleeders are under control (called hemostasis) we enter the abdomen. We make our incision at a specific spot in the abdominal muscles called the linea alba. It is at this spot that there are minimal blood vessels. The linea also has strong tendinous attachments to the muscle, so when we sew it back together these tendons attachments have more holding ability than the abdominal muscles alone. This will prevent a hernia.

Our first view of the spleen once we have entered the abdomen. It is the round and reddish structure at the top of the abdominal opening and just to the left of our surgeon’s finger.

A spleen that is not healthy is friable and can easily rupture when handled. Our surgeon has to gently coax it out to prevent  this from happening.

Once it is finally exteriorized the problem is obvious. At this point we do not know if it is cancerous or not. We do know it is in the process of rupturing and glad we are getting it out now.

Now that we have it ready for removal we have to ligate its blood supply. As you remember from your surgical anatomy above the blood vessels to the spleen are closely related stomach. It is important to ligate the blood supply very close to the spleen so as not to compromise the blood supply to the stomach, leading to serious consequences.

This blood supply can be surrounded by fat. We have to isolate segments before we ligate.

In the center of this picture you can see one blood vessel that is already ligated. On the right our surgeon is in the process of ligating another blood vessel.

We have completed 3 ligations at this point, with many more to go.

Our surgeons work simultaneously, each starting at a different end of the spleen, so they can complete this tedious part of the surgery sooner. Its all about secure ligation of these blood vessels and minimal anesthetic time.

As part of the natural healing process there is a tissue in the abdomen called omentum. It is like a net, and surrounds an organ that might be diseased. For example, a ruptured intestine that is leaking intestinal fluid (extremely irritating to the abdomen and will cause a peritonitis), will have this net surround the intestine to wall off the leak.

In the case of this rupturing spleen the omentum covered the spleen to help prevent further blood loss. These are clots on the omentum from that. At this point in time during the surgery we cannot determine for sure if these are clots or spread of tumor. The report from the pathologist will tell us for sure. It turns out that this time they are clots.

When the spleen is completely removed we complete our exploratory surgery by checking the other internal organs, especially the liver. Once this check is complete we suture the muscle layer (the linea alba) closed. Again, we work as a team, with each surgeon (they are both lefties) suturing the linea until they meet in the center.

Once we have finished suturing our patient, who is already on a pain patch (Duragesic or Fentanyl patch- which is removed in 3 days), is given an additional pain injection and carefully monitored post-operatively. As part of the monitoring we perform a simple blood panel to make sure there was no problem with blood loss during surgery. If the blood loss is significant we will give a blood transfusion with the blood we have already set aside specifically for this patient.

Post operatively we take radiographs of the chest and perform and ultrasound every 2 months for cases of HSA looking for distant and local metastasis.

Occasionally we come across a spleen that is so large it is hard to believe it can get this big. The following spleen was over 8 pounds, removed for a 65 pound labrador named Jake.  Dr. P and Dr. R had to do this one together. Removing it was like delivering a baby!

The size was obvious as soon as we entered the abdomen. At this point in time we were not sure if it was a boy or a girl! Dr. P is coaxing it out of the abdomen at the beginning of the surgery, being very careful not to rupture it.

We had to be very gentle  because it was quite delicate(friable) and already rupturing

Ligating the blood vessels to the spleen was more difficult than usual because of the size, scar tissue, and omental tissue that covered the rupturing spleen

It turns out that this was a hematoma and the dog did fine for several more years. Lucky this spleen did not rupture before the surgery.  Most likely, with a hematoma this large, death would have ensued rapidly.

We also took out a spleen with a large hematoma on this dog named Colt that weighed 14 pounds

ColtJenn

You can learn all the details of this case, and see his surgery, by following this Had to make it live for you to see it. spleen hematoma link. Its a case study and very informative, with lots of cool pictures.

Ancillary Treatment

After surgery we will consult with the oncologists at the Veterinary Cancer Group for further treatment

Post Surgical Treatment

Prognosis

A successful outcome from surgery depends on what disease process is present and how long it has been present.

Splenic Hematoma- good

Splenic Torsion- good

Hemangiosarcoma – guarded to poor.

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Hypertension (High Blood Pressure)

Many cats are living longer lives, and unfortunately, are acquiring diseases that were not commonly seen in the recent past. Hypertension (high blood pressure) is one of these diseases. High blood pressure can be primary, where the cause is unknown. In most animals though, it is secondary to some other disease.

The increase in blood pressure affects many organs, particularly the liver, eyes, kidneys, and heart. Hypertension hastens the progression of these diseases, and substantially predisposes your cat to blindness.

Dogs can get high blood pressure due to various diseases, but we see the problem more commonly in cats, especially as they age. This emphasizes the need for routine exams, blood panels, and blood pressure monitoring for cats as they get older.

The are two main factors that determine blood pressure:

Cardiac output

It is the amount of blood pumped by the heart in a specific period of time. The determinants of cardiac ouptut are the heart rate (measured in beats per minute) and the stroke volume (the amount of blood in ml ejected with each beat of the heart).

Vascular resistance

This is how constricted or dilated the artery is as the blood is flowing through it. A dilated artery has a larger diameter, so less blood pressure needs to be generated by the heart for blood to flow through this dilated vessel. Arteries constantly constrict and dilate, all depending on the needs of the body overall and the specific organ they are supplying blood to. For example, the arteries to your muscles dilate when you exercise. This allows the muscles to receive extra nutrients and oxygen. When you are done exercising they start constricting and blood is diverted to other areas of the body where it might now be needed. Maybe now you are eating a meal and the digestive system needs the added blood flow.

As it turns out, is is cardiac output x vascular resistance that determines the blood pressure. If you get scared, adrenaline secretion will increase the heart rate and your blood pressure will rise due to the increased cardiac output. If you become dehydrated, the stroke volume might decrease due to a lack of fluid, and your blood pressure will decrease due to a decreased cardiac output. Older pets tend to have arteries that are not as elastic as when they were younger, the animal world version of arteriosclerosis. These blood vessels stay constricted more than dilated. This increases the vascular resistance, resulting in increased blood pressure.

Normal regulation of the blood pressure involves a complicated set of metabolic processes. Many body systems are involved, including the nervous system, the renal system, the cardiovascular system, and the endocrine system. It is a highly refined system that can make minute changes in rapid response to changing physiologic needs.

In a nutshell, the kidneys secrete a hormone called renin. This can be in response to a decreased blood flow to the kidneys, stimulation of the nervous system, secretion of hormones like adrenaline (epinephrine), or low sodium levels. Renin will activate the conversion of angoitensin I to angiotensin II in the lungs. Angiotensin II will constrict the blood vessels (increased vascular resistance) and stimulate the secretion of aldosterone. Aldosterone will increase water retention by its effects on sodium. Constriction of blood vessels (increased vascular resistance) and increased water retention (increased stroke volume) lead to an increased blood pressure. Pretty easy huh?

Pathophysiology

Abnormally high blood pressure causes blood vessel damage, particularly in the eye, kidney, heart and brain. These damaged blood vessels will bleed, cause clots, cause fluid buildup in the tissue surrounding the blood vessel, and even tissue death. The mechanism for this is complex.

Hypertension also places excessive strain on the cardiac (heart) muscle. The heart has to pump against more pressure (vascular resistance), causing further deterioration. It becomes a viscious cycle as the problem gets worse and worse. As it progresses the heart enlarges and a murmur might be heard with the stethoscope.

Symptoms

There are no specific set of symptoms of high blood pressure. That’s why its called the silent killer in people. What might appear are the symptoms of the disease that is causing the high blood pressure in the first place.

The primary symptom in cats some owners notice is a sudden onset of blindness, as evidenced by dilated pupils and bumping into objects. Cats that were apparently fine just a day or two earlier are now completely blind. Prior to the onset of blindness an owner might notice other symptoms. These might include weight loss, excess drinking and urinating, vomiting, change in appetite (up or down) and fast heart rate. Monitoring some of these parameters ahead of time is possible to look for subtle signs of diseases. This is explained in our In Home Exam section and our Wellness section. 

Ollie is exhibiting all the classic signs of blindness. Both pupils are dilated and stay that way, even when a light is shined on them. In addition, his left eye shows signs of potential hemorrhage.

Cause

Feline hypertension is almost always secondary to other problems, namely hyperthyroidism and kidney failure. The majority of cats with these two diseases will eventually develop hypertension. Any cat that has been diagnosed with one or both of these diseases should be monitored for hypertension every 3-6 months.

Kidney Failure

Every beat of the heart sends a significant amount of blood to the kidneys. As cats age the kidneys do not function properly, and through complex mechanisms mentioned in the physiology section, the blood pressure will elevate.

Hyperthyroidism

The increased level of thyroid hormone (thyroxine) in the blood stream causes the heart to increase its output of blood, leading to a racing heart and an increase in blood pressure.

Diagnosis

As in people, hypertension is a silent disease. You don’t feel ill, and there are no obvious symptoms until it is too late. Fortunately, we have sophisticated medical equipment that will help us make this diagnosis.

Signalment

Hypertension is found in cats and dogs. There is no breed predilection, but tends to occur more in males and older animals.

History

Older cats that have racing and pounding heart rates, along with blindness, give an indication of hypertension. Hypertension is suspected in cats that have been diagnosed with kidney or heart disease in addition to hyperthyroidism.

Physical Exam

In most cases there are no obvious physical abnormalities. Blood samples that are easily obtained, or pulsate in the syringe when obtained, are another indirect indication of hypertension. The pupils might be dilated, the thryoid gland might be enlarged, the kidneys might feel abnormal, and there could be blood in the urine (hematuria) or nose bleed (epistaxis).

An examination of the retina by a veterinary ophthalmologist will sometimes give an indication of hypertension. There might be areas of hemorrhage or even detachment of the retina. Every blind cat should be seen by an ophthalmologist to check for hypertension, along with other causes of blindness like FeLVFIP, fungal infections, and Toxoplasmosis.

Diagnostic Tests

An important tool in the diagnosis of hypertension is a blood pressure monitor. Cat arteries are very small, and the usual method to detect hypertension in people is not accurate in cats. A special blood pressure unit called a Doppler can be used. Its basis in principle is the Doppler effect (obviously). The Doppler effect is the change in frequency of a sound wave as an object comes towards you then moves away from you. The best analogy of the Doppler effect is the sound a speeding race car makes as it comes towards you, then passes away from you. Coming towards you it has one frequency of sound, going away it has another.

In the case of a Doppler blood pressure unit, it is the movement of red blood cells through the artery that is being measured. During the frequency change that occurs during this red blood cell flow the reflected sound wave goes from the ultrasonic to the audible range.

Taking a blood pressure reading on a cat is more difficult than in a person. Their arteries are very small, and of course, cats are covered with hair. Also, cats don’t sit still, and are easily stressed, which can lead to a false reading. We will routinely take several readings, discard the lowest and highest, and average the rest. Sometimes we find a cat with consistent readings each time, so not as many readings are needed. A cat with a systolic pressure of 160 mm of Hg is suspected of having hypertension, over 170 mm Hg is considered to be hypertensive. In dogs we consider over 180 mm Hg to be hypertension. Sight hounds, overweight, and older animals tend to have higher numbers. These are not hard and fast numbers, just a guideline for each individual case. In many cases of high readings we repeat the blood pressure readings later to check for consistency in the readings, especially  in cats.

To obtain an accurate reading we prefer owners stay with their cat in one of our quiet exams rooms. After clipping the fur on the bottom of the rear foot (we also use the front foot and tail) we set up our equipment. We take our first pressure reading when everything is calm and all equipment is set up. Notice in the video below how calm the cat is and how quiet the atmosphere for an accurate reading.

Low blood pressure can be of significance in animals. Usually this is encountered during anesthesia. Our Doppler unit allows us to monitor the blood pressure during anesthesia and make corrections as needed. We also encounter low blood pressure during shock, trauma, bleeding, and from certain medications.

Treatment

Underlying treatment of the disease that is causing the hypertension is sometimes all that is needed to prevent hypertension. In kidney disease the use of K/D food, with its decreased salt (sodium chloride) might be beneficial.

If your cat has hyperthyroidism we will treat for that, and usually the blood pressure returns to normal

If hypertension still persists after treating the primary problem then we sometimes will use specific medications to lower the blood pressure:

Heart Drugs

ACE inhibitors like Enalapril or Lotensin (prevent conversion of angiotensin to angiotensin II, thus decreasing stroke volume and vascular resistance)

Beta-adrenergic blockers like Propranalol or atenolol (decrease the heart rate)

Calcium channel blockers like Norvasc (decrease vascular resistance). This is the most common one we use in cats.

Diuretics

Lasix or aldactone (decrease the stroke volume)

Vasodilators

Hydralazine (decrease vascular resistance)

Blind cats need to be placed on a drug called Norvasc to rapidly lower the blood pressure. There is a chance of regaining sight with the use of this drug, especially if utilized as soon as blindness is noted. Cats that are on this drug should have their kidney tests monitored 2 weeks after starting Norvasc, then every 3 months.

The best treatment for hypertension and its associated blindness is prevention. Any cat over 8 years of age, or diagnosed with kidney disease, diabetes mellitus or hyperthyroidism, should be monitored periodically for hypertension. This will allow diagnosis of the problem before it causes blindness.

Monitoring

All pets with hypertension should have their blood pressure checked every 3 months. In addition, blood panels, thyroid tests, urinalysis, and eye exams should be performed every 3-6 months.

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