Month: November 2015

Mammary Cancer (Breast Tumor)

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These preventable tumors are the most common tumor in female dogs as they age. They do occur in males, but this is a rare occurrence. Up to 50% of these tumors in dogs are malignant. The specific cause of this problem is unknown, although there is a very strong correlation to hormones, especially in the dog.

Some tumors become so large that they can become ulcerated and painful, leading to the potential of an infection that spreads to the rest of the body (sepsis or septicemia). Why someone would wait for a tumor to get this large before seeking our medical care is beyond us. 

It is an accepted fact, proven over many years, that if you spay (ovariohysterectomy) your dog  prior to its first heat cycle there is a negligible chance your pet will get this cancer. The longer you wait once your pet starts its heat cycle the greater the chance it will get this problem.

Mammary tumors account for 17% of all cat tumors. They are the 3rd most common tumor in cats, after skin and blood cancer. Even though cats get this problem half as often as  dogs, almost all of them are malignant.  Intact females are at highest risk, although it does occur in males on rare occasion. Even though early spaying in the cat does not seem to yield as much protective effect as in the dog,  you can still decrease the incidence of this tumor by up to 60% by spaying early.

Mammary tumors are very common in rats.

Sometimes by the time we see them they are as large as the rat

At the end of this page are two short videos of surgery using the laser to remove a mammary tumor. They are graphic in nature, and not suitable for all viewers.


Terminology

It is helpful to be exposed to several medical terms that will be used later in this page:

tumor- abnormal tissue growth cancer – malignant tumor
malignant- tumor that spreads to other organs  causing substantial organ failure benign- tumor that does not spread or cause organ failure
mammary or mammae – breast tissue lymphatics- complex of organs that drain excess fluids
lumpectomy- removal of part of the mammary gland simple mastectomy- removal of the entire mammary gland
regional mastectomy- removing the whole affected gland along with other glands unilateral mastectomy- removal of all the glands on the affected side along with underlying tissue and lymphatics.
metastasis- spread of tumor, usually through the bloodstream or lymphatics, to other organs. colostrum- first milk that contains antibodies

Anatomy

In dogs there are 5 sets (varies from 4-6) of mammary glands in a chain, for a total of 10 mammae. From top to bottom they are called:

  • Cranial thoracic
  • Caudal thoracic
  • Cranial abdominal
  • Caudal abdominal
  • Inguinal

From top to bottom you can trace the nipples. How many nipples do you count on this dog?

Nipples even show up on a radiograph. Can you see the three that are apparent on this radiograph?
They are the 3 small and circular white spots- there is one towards the top left, one towards the lower right, and one at the lower left.

The inguinal mammary tissue tends to the largest, and produces the most milk. Due to its size this area can look like it has a tumor when in reality it is normal. If you feel an enlargement here one of our doctors should check it to confirm it is nothing more than fat. This is the most common mammae for a tumor to form in the dog.

The upper mammary glands drain towards the auxillary (arm pit) lymph nodes. The inguinal mammary glands drain towards the inguinal (groin) lymph nodes. The middle mammary tissue (caudal thoracic and cranial abdominal) can drain in either direction. You can learn much more about lymph nodes by following this link.

In the cat there are 4 pair of mammary glands. The cranial gland are the most common ones for tumors to occur.

For a little comparative anatomy fun; manatees, and primates only have two mammary glands.

Physiology

Mammary glands are modified sweat glands. They reside in the subcutaneous (SQ) fat, which is the fat just under the skin but above the muscle. The primary function of the mammary glands is to produce milk and hormones.

Milk contains:

  • Water
  • Lactose (the milk carbohydrate)
  • Fat- much higher in some animals than others, usually in the form of tryglycerides.
  • Protein- Also varies quite a bit by species. The primary protein in milk is caled casein.
  • Mineral, vitamins, and enzymes.

Whale and seal milk has 12x as much fat, and 4x as much protein, as cow’s milk. Cow’s milk has less protein and fat than cat and dog milk, which is why orphan kittens and puppies do not do well on it. It takes between 500 and 1000 liters of blood to make 1 liter of milk in the cow.

Numerous hormones are involved with the production of milk:

  • Progesterone
  • Insulin
  • Glucocorticoids (cortisone)
  • Prolactin
  • Estrogen

In the first week of lactation the milk that is produced is called colostrum. This milk contains antibodies to protect kittens and puppies from routine diseases like Distemper and Parvo.

Hormone receptors for estrogen and progesterone are present in the dog. In the cat there are usually progesterone receptors, the estrogen receptors are not very prevalent.

Classification of Mammary Tumors

Mammary tumors can be malignant or benign. In dogs, up to 50% are malignant. In cats, almost all mammary tumors are malignant (adenocarcinomas). Although there are histologic variations on this, these are the main classifications. The more common ones are at the top of each list:

Benign

  • Adenomas
  • Mixed tumors
  • Fibroadenomas
  • Mesenchymal

Malignant

  • Tubular adenocarcinomas
  • Papillary adenocarcinoma
  • Anaplasric carcinoma
  • Sarcomas
  • Solid carcinomas
  • Mixed

Cause

The exact cause of mammary tumors is unknown, although there is a strong correlation to hormones. It has to do with estrogen and progesterone receptors on the tumor. These receptors are present in up to 70% of canine mammary tumors, and 10% of cat tumors. For this reason we tend to stay away from estrogen and progesterone type drugs when treating other diseases.

If your dog is spayed (ovariohysterectomy) before it goes into its first heat cycle, the chances this dog will get breast cancer later in life is virtually nil. A typical female dog will go into heat at 9 months of age, although this varies. If your dog is not spayed until after its first heat cycle the risk of breast cancer can be as high as 8% later in life. Another heat cycle prior to spaying gives a 26% chance of cancer later in life.

Another way to minimize the risk of mammary cancer is to keep your dog at its proper weight.

It is also beneficial to spay a cat early in life. This is especially important in cats because most of their breast tumors are malignant.

Symptoms

The beginning signs of breast cancer can be hard to detect because they are so subtle. Also, mammary tissue tends to hang down hiding any swelling or enlargement.

You should examine your dog or cat weekly while you are playing with it or petting it. Most pets love to have their bellies scratched, which is an ideal time to do your exam. We will show you how to do an In-Home exam next time you come in to check for any problem your pet might have and diagnose and treat it early when there is so much more that can be done to effect a cure.

Run your hands along both chains of mammary tissue from top to bottom feeling for any difference in symmetry. Palpate each gland individually and gently for swelling, discharge, ulceration, hardness, extra warmth, nodules, or discomfort.

Look at each mammary gland, especially each nipple, for any signs of discharge, inflammation, or swelling. Any of the above symptoms are an indication to bring your pet in for us to perform an exam and even run some tests if we think a problem is present. Other symptoms to look for are lameness, swelling of the limbs, or difficulty breathing.

Diagnosis

thorough approach is needed for a correct diagnosis of mammary tumors. In every disease we encounter we follow the tenet’s of the diagnostic approach to ensure that we make an accurate diagnosis, and also so that we do not overlook some of the other diseases that are common in pets .

Diagnosing some cases of mammary tumors is straightforward, especially if the disease has been present for a significant amount of time before a diagnosis is made. Unfortunately, in these cases the disease can be well entrenched, and malignant tumors have had significant time to spread.

  1. Signalment

    This tends to be a disease of middle-aged and older unspayed female dogs and cats. Even though it can occur it is rare in males.

    Some breeds have a higher incidence:

    • Hunting breeds- retrievers, pointers, and spaniels
    • Terriers- Boston, fox, and Airedale
    • Dachshunds
    • Poodles
    • German Shepherds

    Some breeds have a low incidence:

    • Collies
    • Boxers

    Siamese cats  have twice the risk as other cats, and their tumors tend to me more malignant than other cats. Domestic shorthair cats (DSH) have a higher incidence than other cats also.

  2. History

    Due to the location of the breast tissue it is easy for an owner to overlook this problem . Pets with early breast cancer do not show the usual symptoms of disease in general. They are usually active, eating well, maintaining normal weight, and have normal bathroom habits. A small tumor that is growing can easily be present for months before an exam is performed. This adds to the problem and can make treatment more complicated.

    Some owners find a swelling, discharge, or a growth while bathing or petting their dog or cat. Any suspicious area should be checked by one of our doctors to determine if there is a growth, swelling, or just normal breast tissue.

    When the tumor has already spread some pets might have difficulty breathing (dyspnea) due to buildup of the tumor in the lungs, or lameness due to spread of the tumor to the bones. In cats the dyspnea can be due to fluid buildup in the thorax (pleural effusion).

This cat has a mammary tumor at the nipple. This is the only sign of disease it had, and can easily be missed if you are not observant. This problem was easy to spot once we clipped the hair in preparation for surgery.

 

Intact female dogs can have a false pregnancy 2-4 weeks after their heat cycle that will cause the mammary tissue to swell and mimic a tumor. It is due to the progesterone that is produced during the heat cycle, and the problem will resolve on its own in a few weeks.

Other diseases that mimic breast cancer include an infection called mastitis, skin tumors, and an inguinal hernia. In cats the inguinal fat pad can be enlarged and mimic a tumor. Foreign bodies like BB’s (not all that uncommon for a cat to be found with a BB when we take an X-ray) feel like tumor nodules.

  1. Physical Exam

    In some cases a swelling or growth is found in the breast tissue during an exam for a different problem, or during a routine wellness exam.

    Nodules might be small and solitary, or the whole mammary chain can be affected. Nodules that are adhered to the skin or underlying tissue, are ulcerated, painful, or swollen tend to be malignant. Nodules that are rapidly increasing in size also tend to be malignant. There might be a discharge from the nipple, and your pet might be running a fever.

    Here are some typical lesions in a cat





    Whenever your pet is placed under anesthesia we perform a thorough exam, including mammary tissue. This is an ideal time because your pet is not moving, it is commonly on its back and we have good access and visualization of the area, and the muscle relaxation allows us to thoroughly palpate small nodules. Your pet can have a malignant tumor and show minimal to no symptoms.

This dog is under complete general anesthesia just prior to her spay surgery. With the hair clipped away at her abdomen you can see the good access we have to the mammary tissue.
This enables our doctor to perform a thorough exam of all the mammae

Enlarged lymph nodes due to spread of  tumor might also be noted. A lymph node can contain the spread of tumor cells and still appear and feel normal. Cats frequently have the spread of their tumor to the lymph nodes.

One of the typical lymph nodes we will check during an exam are the axillary (arm pit)

In this picture that cat’s head is to the right, and we are checking the inguinal lymph nodes on the insides of the rear legs.  If a malignant tumor has spread through the lymphatic system it can cause swelling of the rear legs due to blockage of the lymphatic drainage system.

  1. Diagnostic Tests

    Any pet suspected of having a mammary tumor needs routine tests as the first part of the diagnostic process.

    Blood Panel

    A CBC (complete blood count) and biochemistry panel should be run on every dog or cat 8 years of age or more, especially if they have any of the symptoms of mammary disease

    The CBC checks red and white blood cells. We are looking for signs of infection, cancer, anemia, or excess production of red blood cells. If your pet has mammary cancer it might also have inflammation or a secondary infection. We might get a clue of this from the CBC.

This pet might have an inflammation or infection as evidenced by the increase in the white blood cells. This is called leukocytosis. If the physical exam findings are consistent with an infection then we might put this pet on antibiotics before initiating any other treatment at the moment.

The next part of the blood panel is called the chem or biochemistry panel. It checks the internal organs, along with electrolytes and specific physiologic tests like blood sugar.

Dogs and cats with mammary tumors tend to be older, so Geriatric Diseases are more prevalent. Since surgery is usually a major part of treatment we need to make sure the internal organs are ready for anesthesia. This is particularly true of kidney and liver disease. Some pets with mammary cancer will have a high calcium level on this panel.

This pet has some abnormalities, especially the low protein level, that need to be addressed prior to surgery

In some cases we might run a clotting panel looking for any signs of a disease called disseminated intravascular coagulation (DIC). This can occur when there is an inflammatory carcinoma.

Urinalysis

The urinalysis on this pet is normal

Cytology

In this test we insert a tiny needle with attached syringe in the mammary tissue. It is a tiny pin prick, and is the same kind of needle we use to give vaccines.  Some cells are aspirated into the syringe and then gently pressed on to a microscope slide.

The pathologist looks at these cells to give us an idea of what we might be up against

In some cases we use this test, especially if it is difficult to differentiate inflammation from an actual tumor. Its also gives us an idea of just how malignant or non-malignant the tumor is, so we can adjust our surgery accordingly. In cats we assume the tumor is malignant and usually skip this test and go right into surgery.

Even though it can be a  useful test, it only looks at a small portion of the mammary tissue. So it is used only as ancillary information prior to surgery and not to make a final diagnosis. Also, multiple tumor types might be present, and you can make the wrong interpretation with just this test.

Aspiration of a local lymph node can also be helpful to detect evidence of any spread of a tumor. In cases of extensive mammary involvement, usually the whole chain, we might completely remove the lymph node that drains that area. This gives the pathologist much more tissue to work with to ascertain if there has been a spread of the tumor.

In cats that have fluid buildup in their thorax we can submit this fluid for cytology also.

Radiography

Radiography (X-Rays) are a very important test prior to surgery because up to 50% of the dogs with malignant breast cancer have spread of the disease to the lungs at the time of their exam. We need to confirm that there is no spread (metastasis) of the tumor to the lungs or else surgery might not be indicated. We take 3 different views of the chest to determine if the lungs are clean.

In this chest radiograph we have placed black arrows at some of the white and round areas that are the spread of the tumor in the lungs. Compare it to the normal dog radiograph below if you need to.

Normal dog chest radiograph

This is what a mammary tumor under the skin looks like on a radiograph. It is that round white object on the bottom

Some cats will show signs of difficulty breathing. It can be subtle, so it behooves you to spend some time every day observing your pet for any changes that indicate a problem. A normal respiratory rate in a cat at rest is 30 times per minute. Check your cat as part of your routine In-Home exam to see what is normal for your pet. What you are looking for is a change in the respiratory rate, and if it increases we should examine it.

This is a normal cat chest radiograph. Notice the large and normal black lung area.

In this radiograph from a problem cat there is fluid throughout the thorax and you cannot see normal black lungs. The lungs have collapsed due to the fluid in the thorax. The only lung tissue you see is the slightly dark leaf-shaped structure towards the top of the thorax.

After oxygen therapy for stabilization we drained some fluid off the thorax. This caused an immediate improvement in breathing. A radiograph taken soon afterwards shows improvement as evidenced by the increase in the normal amount of black lungs visualized. When this fluid appears due to the spread of a malignant tumor from a mammary gland the prognosis is poor.

In some cases a radiograph of the bones will show spread of cancer. If a radiograph is taken of the abdomen some malignant cancers will show an enlarged sublumbar lymph node. Ultrasound is beneficial here in assessing local lymph nodes and abdominal spread from a malignant mammary tumor.

This abdominal radiograph shows the location of where the sublumbar lymph node is normally located. It is not apparent in this view, so it is not enlarged.  The K stands for kidney and the B stands for urinary bladder. Ultrasound tends to be a more accurate way to assess abdominal lymph node enlargement when compared to radiography.

Can you see the enlarged sub lumbar lymph nodes in this radiograph?

  1. Response to Therapy

    One of the tenets of the diagnostic process is whether or not a treatment that is instituted actually corrects the problem. Surgery is the main form of treatment, so response to treatment does not apply as much as to other diseases that are more medical in nature and treated with drugs.

Treatment

Graphic pictures and movies to follow.

The treatment of choice for mammary tumors is surgery. Chemotherapy, radiation therapy, nor hormonal therapy have any proven benefit.

It is routine to spay (OVH) an intact female dog prior to or during surgery to remove an affected mammary gland. Even though at this usually late date it will not prevent more tumors from appearing, it will prevent uterine infection (pyometra) and uterine cancer, and might even prevent hormone influence on existing tumors.

If the gland is infected we might use antibiotics to reduce the swelling and inflammation. This will allow us to see the margins of the tumor more readily during surgery.

When your pet is relaxed under anesthesia, and the hair is clipped away prior to surgery, we will examine the mammary glands again. It is not uncommon to discover a small tumor that was missed during the routine exam.

Any pet under anesthesia is closely monitored with the latest equipment

Our anesthesia page (link above) has detailed information on how we anesthetize the wide variety of animals we care for at Long Beach Animal Hospital.

Once our diagnosis and ancillary tests are complete we will remove the mass surgically. Depending on the location, size, duration, species, and physiologic status of your pet, we might do a lumpectomy or remove part or all of the chain. In extensive cases we might have to remove one chain of tissue in a first procedure, then the other chain several weeks later when the first chain has healed. Since cats usually get malignant tumors it is common to remove the whole chain on the affected side.

We routinely use our laser for this surgery. This dramatically minimizes post operative bruising, discomfort and swelling. We can’t emphasize enough how important the use of the laser is in this surgery. Prior to our laser these dogs and cats would have extensive bruising and swelling of the sensitive mammary tissue. We would place many sutures under the skin to prevent fluid buildup and discomfort.

We no longer need to with the laser. Dogs and cats that have this surgery, even when a radical surgery is performed, routinely go home the same day and have minimal discomfort. When laser is used with routine pain medication your pet will usually be eating and resume normal activity within 12-24 hours.

We use the laser to remove these tumors due to its tremendous ability to control bleeding during surgery, and swelling and pain after surgery. As you can see from the picture above there is no blood in this dissection of this mammary cancer. Without the laser it would have been very bloody.

In all these surgeries we remove a wide margin of tissue to ensure we removed all of the tumor. In all cases our goal is to remove all of the tumor and get what are called “clean edges” by the pathologist. This means there is no microscopic signs of tumor cells in the tissue submitted for analysis. This makes for a much better prognosis.

This is a typical mammary tumor in a cat prepped, draped, and ready for surgery

A wide surgical incision is made with the laser to makes sure we have removed all of the cancer in this cat. The lack of bleeding due to the laser is obvious. 

What the suture site looks like when we are finished. The rubber tube is called a penrose drain tube.
It is used to decrease swelling during healing, and is removed in 3-5 days. In most of our laser surgeries we do not need to put this tube in since there is no post-operative 
swelling.

Before our patients wake up we use the Cold laser to minimize swelling at the incisions site and aid the healing process

We use it in many of our surgeries where an incision is made in the skin. Here it is being used after a dog neuter.

We make sure our patients are comfortable after a mammary chain removal. This involves pain medication prior to, during, and after surgery. It also involves the use of the laser during the surgery and local anesthetic at the incisions site. Finally, after we use the Cold Laser on the incision site, a comfortable wrap is put around the chest with padding underneath. 

Since cats frequently get malignant tumors we commonly remove the whole chain of mammary tissue on the affected side. We might also remove the closest lymph node to look for metastasis.

This is a report on a cat with a malignant breast cancer

When we remove the mammary tissue on one whole chain there is a long incision. With the use of the laser and routine surgical and post surgical pain medication these cats recover rapidly from surgery.

Click on the link below to see a laser lumpectomy surgery on a cat. Notice how little bleeding there is when the laser is used.

Lumpectomy

This next cat has more gland involvement and requires more surgery. Notice how diseased the tissue appears and the lack of bleeding when using the laser. As the surgery progresses you can see milk coming from the gland.

Click here to learn more about the laser and how it is used in many types of surgeries at our hospital.

Post surgery treatment

Diseased mammary tissue that is removed during surgery is submitted for histopathic analysis. The pathologist will determine the type of tumor and will also stage it. Stages usually go from 0 – 3.

  • Stage 0- Tumor cells are limited to the ducts within the mammary tissue
  • Stage I- Tumor cells are in the ducts and the supportive or framework tissue of the mammae (called stroma)
  • Stage II- Tumor cells are in the blood vessels, lymphatic tissue, or regional lymph node
  • Stage III- Tumor cells have spread through the body- usually lungs or bones

Chemotherapy is used when we cannot remove all of the tumor of if your pet has inflammatory carcinoma.  Chemotherapy for mammary cancer tends to be unrewarding. Some of the drugs we use, which should be under the direction of a veterinary oncologist, include:

Dogs

  • Fluorouracil
  • Doxorubicin
  • Cyclophosphamide
  • Cisplatin
  • Carboplatin

Cats

  • Doxorubicin
  • Carboplatin
  • Mitoxantrone
  • Cyclophosphamide

Tamoxifen, a product commonly used for human breast cancer, is ineffective and has the potential for serious side effects in dogs.

In some dogs and cats the tumor is not resectable. This occurs in inflammatory carcinomas. In these cases we used what is called palliative therapy. We attempt to keep them comfortable with antibiotics, pain medication, fluids, assist feeding, good nutrition, and lots of TLC.

Prognosis

If your pet’s tumor is benign and completely removed, then it will be cured of the disease. Benign tumors can appear in other glands though when only a nodule is removed and the gland is left intact.

If the tumor is malignant then it is hard to predict due to the variable nature of the malignancy. Low grade malignancies can be cured with surgery. Those tumors with a higher stage of malignancy or ulceration can recur and spread within the first year of surgery. Some of the factors that influence prognosis are:

  • Tumor size- tumors smaller than 2-5 cm have the best prognosis for malignant tumors.

If the tumor is smaller than 2-3 cm many pets will live up to 3 years.
If the tumor is larger than 2-3 cm most pets will live for 6 months

  • Tumor histology- Sarcomas, carcinomasarcomas, and malignant mixed tumors have a poorer prognosis than carcinomasadenocarcinomas. Inflammatory carcinomas have a very bad prognosis.
  • Tumors classifed in histologic stage II or III carry a worse prognosis.

Cats with malignant tumors usually do not survive more than a year. Their tumors grow rapidly and spread to the lungs early, usually before a pet owner is aware and brings them in for diagnosis and treatment. Prognosis for a cat depends on 5 factors:

Tumor size

If there is spread to the lymph nodes

Histologic grade:

Stage I- > 24 months

Stage II- 12-24 months

Stage III- 4-12 months

Stave IV- 1 month

Invasion of the lymphatics that drain the gland

Siames cat has a poorer prognosis than domestic cats

This is the report on the cat with the nipple that was inflamed. We showed you the picture of this tumor earlier when we talked about how easy it is to miss some of these tumors.

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Fractured Jaw in a Cat

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It is not uncommon for a cat to break its jaw due to a traumatic incident; usually falling from a height or being hit by a car. The lower jaw (the mandible) usually fractures right in the middle of the chin which is very painful and renders the pet unable to use its jaw to eat. Fortunately for most cats, they heal very well when the jaw is wired back together. Now if only they can remember not to run across the street again……

This area contains graphic pictures of an actual jaw repair performed at the hospital. It may not be suitable for some children (and some adults also!).

Symptoms and Diagnosis

In almost all cases of jaw fracture the diagnosis is obvious. The pet is drooling, the jaw hangs down, and it is unable to eat. There are frequently other signs of trauma present somewhere on the body.

Palpation of the jaw (under anesthesia) reveals the extent of the problem. The location of this fracture is called the symphysis of the mandible.

Treatment

The two halves of the lower jaw (the mandible) are wired back together with stainless steel wire. The wire is kept in place for approximately one month, then the cat is anesthetized again and the wire removed. Most cats begin eating within 1-2 days of the repair, and only rarely do we have to place a feeding tube in so they can ingest adequate calories. If there are no other problems almost all cats heal completely.

A special stainless steel wire is placed around the lower jaw. To be anchored properly, and to stay in place until healing is complete, the wire must pass through the underside of the jaw.

The surgeon then aligns the 2 fractured pieces and gently tightens the wire. When finished the wire passes under the tongue but over the lower jaw.

The ends of the wire pass out through the skin under the jaw. The wire is pushed up against the skin so it does not interfere or snag on things.

This radiograph gives an inside view of the wire.

The roof of the mouth (the hard palate) is bruised because this cat was hit by a car. Fortunately the hard palate was not fractured, so no further treatment was needed.

The tongue was severely bruised also. This is the type of lesion, that when added to the fractured jaw, can prevent a cat from eating. Luckily the bruised tongue healed within a few days and this cat started eating soon. If not, we would have put a feeding tube in.

Jaw fractures can be quite painful, so it is common for us to use pain medication.

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Feeding Tubes

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In comparison to people, feeding tubes in animals are not routinely used in terminal cases to prolong life. They are used to help an animal get over a temporary problem and return to good health.

Most species of animal can go many days without eating. This is not true for cats, especially when they are sick. Several days of not eating (anorexia) can have serious consequences in cats and lead to failure of important organs like the liver.

In addition to cats we use feeding tubes in our practice for turtles and tortoises that are not eating.

Causes of Lack of appetite

Internal organ diseases like hepatic lipidosis, infections, FeLV, and fevers, along with anatomical problems like a broken jaw can all prevent a cat from taking in adequate nutrition. In addition, all of these diseases increase caloric needs for healing to occur, so a lack of appetite in a diseased cat is an important problem to address.

The yellow discoloration to this cats gums is called icterus, more commonly know as jaundice. In this specific case the icterus is caused by liver disease because this cat has hepatic lipidosis. Feeding tubes are commonly used in these cats because they have stopped eating.


Short Term Treatment Options

Several options are available to give adequate nutrition to cats that are not eating. Many times they begin eating after we rehydrate them with intravenous fluids, especially if they have kidney disease. Sometimes we also need to assist feed them with special foods that are easy to administer and digest. Some cats will even start eating after we give them valium intravenously. Cats that have sugar diabetes (diabetes mellitus) might begin eating after we control their blood sugar level with insulin. Cats that are in pain from serious injury like a broken jaw might start eating when we give them pain medication.

This liquid diet called Clinicare is often used to provide both fluid and nutrition on a short term basis. It can be given orally or through a tube.

Another food used to provide short term nutrition is called A/D. It is also used for long term nutritional support in some cases. It can also be given orally by just putting it in your pets mouth. It can also be given through a tube when some water is added to it.


Medium Term Treatment Options

A nasogastric tube is an option that sometimes works well for several days. This tube is passed through the nostrils and into the esophagus. It is taped and sutured in place. It has the advantage of easy placement and maintenance. The main problem is that the small diameter of the tube that is used only allows a liquid diet (CliniCare). To give an adequate amount of calories on a long term basis with this liquid diet would mean giving a volume of liquid that is far too much for the digestive system to handle, and the cat will usually vomit.

Another medium term treatment option is tube feeding. In this technique we fill a syringe with A/D and attach a small rubber feeding tube to the end. We gently pass this tube into your pets esophagus and give it the full amount of food that is in the tube. It has the advantage of using a food source (A/D) that is more solid than a liquid diet (CliniCare), so your pet receives more of its needed calories. It also has the advantage of minimal discomfort since no tube is left in for long periods of time. Some cats will begin eating on their own after only 1 or 2 feedings with this technique.

Long Term Treatment Options

  • PEG Tube

    A very effective solution to long term feeding is a PEG tube. PEG stands for Percutaneous EndoGastric. It consists of a tube that passes from the inside of the stomach, through the abdominal body wall to the outside. It allows the long term use of food that will give adequate nutrition. Its first disadvantage is difficult placement. It is usually put in with a special instrument like an endoscope, or is placed surgically during an exploratory surgery of the abdomen. Both methods require general anesthesia. In addition, a further disadvantage is the potential for infection in the abdomen at the site the tube passes out of the stomach.

    In this picture you can visualize the PEG tube that is exiting from the stomach after an exploratory surgery.

  • Esophagotomy Tube

    In terms of ease of placement, cost, and effectiveness, one of the best options for long term feeding is an esophagotomy tube. It does not require specialized equipment or exploratory surgery, and can usually be placed with sedation only. Serious complications are rare, and usually consist of regurgitation of food if too much is given too rapidly, especially in the first few days of feeding. This problem tends to go away by itself.

    The esophagotomy tube passes from the left side of the neck into the far end of the esophagus. The tube is measured to ensure that the proper length is passed, and that the tube does not go into the stomach. This picture shows the measurement of the tube.

    This is the appearance of the tube immediately after insertion and suturing to the skin.

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    When it is bandaged only the tip where you will insert the food is visible.

    An x-ray reveals the path of the tube. The arrows on top outline the tube that is outside of the neck and under the bandage and along the back. The arrows on the bottom are the feeding tube as it passes inside the esophagus from left to right. As planned, it goes partway down the esophagus and does not enter the stomach. The white structure just below and to the right of the tube in the esophagus is the heart. The tube never touches the heart because it stays in the esophagus.

    Here is another view. Click on it for larger size.

    tuberad

Feeding Technique

A food that is routinely fed through a feeding tube for long term maintenance is called A/D. We have a handout that gives you detailed information on this food. We will let you know how much to give and if we want any supplements added. You usually need to add a little water to it to so that it can flow through the feeding tube.

If a PEG tube has been put in then the food you administer goes directly into the stomach. When food is given through the esophagotomy tube it partially fills the esophagus temporarily until it flows into the stomach. In both cases give the feeding mixture slowly and usually at room temperature or slightly warmed.

You will be feeding several times per day throughout the day. After the feeding you need to flush the tube with a small amount of warm water. If it becomes clogged in spite of flushing, place a small amount of cola or papaya juice in the tube until it dissolves the clotted food.

One of our nurses will give you detailed instruction in how to use one of these tubes before your pet leaves the hospital. If you have any difficulty with this tube we are here to help you, so please let us know if you need assistance after you return home. We would like to check your pet and the tube on a weekly basis until it is removed.

The amount of time the feeding tube stays in varies from weeks to months. Only when your pet is eating well and putting on weight will we remove it. An added advantage to the esophagotomy tube over the PEG tube is the ease of removal. On occasion the PEG tube can cause an intestinal blockage when removed because the tip of the tub remains in the stomach after removal and must pass through the intestines to be eliminated.

The overwhelming majority of cats respond positively to long term tube feeding. If your pet consistently vomits then we will put it on some medication to minimize this usually temporary problem.

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Feline Radiographs (X-rays)

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The first series of radiographs are before we had our digital radiography. If you click on some of them they will increase in size.

Cat that was shot in the neck with a pellet

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Wires in a fractured mandible (lower jaw)

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Foreign body in the stomach

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Bone plate for fractured radius

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This cat has fluid in the thorax. Compare it to the  normal chest rad below

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Abdominal Hernia

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Pets that roam outdoors are prone to numerous traumatic injuries. Fighting with other animals, and getting hit by a car, are some of the more common ones. This page shows a surgical procedure to correct an abdominal hernia in a cat named Sundance that was hit by a car.

In this case the hernia was caused by a blow to the abdomen by the car. The blow was strong enough to tear a large hole in the abdominal muscles that surround the abdomen. The small intestine went through this hole and was trapped between the muscle and the underside of the skin. This needs to be corrected because the blood supply to the intestines can be compromised while entrapped in this abnormal location. This will cause a segment of the intestines to die with subsequent loss of life as a possible outcome.

This page has graphic surgery pictures. At the end of this page are autopsy (correctly called necropsy in animals) pictures that are also graphic in nature.

Diagnosis with Radiography

Our physical exam gave us an indication there was a hernia when we palpated the abdomen. To help us confirm the diagnosis we took a radiograph. Radiographs are taken for numerous reasons on every pet that is hit by a car. These pets can have trauma to the chest, broken ribs, herniation of abdominal contents into the chest, and ruptured internal organs like the urinary bladder. The radiograph helps us determine if any of these problems exist. In this case, the radiograph helped verify that Sundance had an abdominal hernia. He also had a fractured pelvis which would heal on its own if he was confined and rested for one month.

In addition to an abdominal hernia, which you will learn more about soon, animals that are hit by cars also can get a diaphragmatic hernia. In this hernia, the abdominal organs like liver or stomach have literally torn through the diaphragm (muscle of respiration) and are sitting in the chest. Needless to say, these are serious injuries. We will show you pictures of this at the end of this page. Lets look at how we make a diagnosis of a diaphragmatic hernia with radiographs.

 The arrows are pointing to a normal diaphragm. The lungs are the dark areas. Use them for comparison to the abnormal radiograph that follows.

This is the radiograph appearance of a cat with a diaphragmatic hernia. Several abnormalities are apparent:

The windpipe is pushed upwards to the top of the chest

The lungs are not black throughout the whole chest

The diaphgram is not visualized at the bottom

The heart seems huge because the liver and stomach are pushing up against it from below

A different case with a diaphragmatic hernia. It just looks like a big and round heart, but it has a diaphragmatic hernia like above.

This dog has 2 fractured ribs at the arrows. Can you see them?

This view of the same chest might help a little. The fractures could easily be missed in the above view, verifying how important it is to take 2 views.

This is a radiograph of cat with a fractured pelvis that is more severe than the one Sundance has. Do you see the fracture on both sides?

Presentation

Sundance was presented to us with a history of being gone for 5 days and lethargy. Most cats that are hit by a car are in a state of shock and can die if not treated with intravenous fluids. Sundance is lucky he survived being hit by a car without any shock therapy.

Our exam revealed a swollen and bruised area just under the skin in the right inguinal area, which made us suspicious of a hernia. Bruising is very common in such small animals that have been hit by a car, so it does not necessarily mean there is an abdominal hernia.

Surgery

Any pet that has been traumatized so severely that it has a hernia has an added anesthetic risk. We take special precautions to minimize this risk.

Surgery-Monitor

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.

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Once our surgeon has scrubbed up and is in a sterile gown, gloves, and mask, the surgery begins

In most hernias we make an incision directly over the hernia and proceed to make the repair. In this case, the hernia area had extensive swelling due to the fact that it had been present for several days before we saw Sundance. Also, the herniated area was near the area where we routinely make an incision to enter the abdomen for an ovariohysterectomy (spay). In this case it was decided to make an incision directly in the center of the body like a spay surgery, and repair the hernia through this incision.

The following section contains graphic surgical pictures of the actual hernia repair we performed on Sundance.

Lets get our orientation before we show surgery pictures. Our patient is on her back, with her head towards the top, and the abdomen clipped of hair. Our patient is already under anesthesia.

The white arrow shows the area of the hernia on the inside of the right rear leg. This is called the inguinal area. It is difficult to visualize the swelling from this view.

This second arrow in the middle of the body shows the location of our incision into the abdomen

The incision directly in the middle of the body was much longer than our typical spay incision. You can see our surgeon starting the incision.

We dissect through the tissue under the skin (called the subcutaneous tissue) until we encounter the rectus sheath, an area where the abdominal muscles come together. This area is very tough, and is used to hold the abdominal muscles together when we suture our patient back together.

The rectus sheath can be seen here as the large white glistening area between Dr. P’s finger. A horizontal incision is made directly through this layer in order to enter the abdomen and find the hernia.

The tear in the abdominal muscles was 4 inches long. It can be visualized here as the horizontal opening towards the bottom of this picture, just under Dr. P’s finger. A large segment of the small intestines was found caught in this hole, and was gently removed just prior to this picture.

Intestines do not belong in this area, and are easily damaged when trapped in an opening this size, especially for 5 days in this case. In this picture Dr. P is carefully checking them to make sure their blood supply in intact.

Here is a different case showing the bruising and compromised blood supply that can occur when the intestines are trapped

Intestines are not the only organ that can be bruised during abdominal trauma or a hernia. The kidney on the left has been traumatized as evidenced by the severe bruising when compare to the other kidney.

A special suture is used to sew the herniated muscle opening shut. It will provide the strength needed to hold the muscle together until healing is complete. Eventually the suture will dissolve.

You can view the partial closure of the opening in this picture as Dr. P sutures the muscle from right to left in the picture.

The muscle closure is now complete. The hernia was so large that additional sutures were placed over this layer for added strength.

The intestines were not the only abdominal organ trapped in the hole in the muscle. The omentum is tissue that naturally resides in the abdomen. When an abdominal organ is traumatized, as the intestines were in Sundance’s case, the omentum migrates to this area and covers the injured tissue to help in the repair process.

In this picture our surgeon is trimming off a piece of omental tissue that is discolored at the tip

It is important to check all the abdominal organs for injury. After the unhealthy omental tissue seen above was trimmed, Dr. P methodically went through all the abdominal organs and checked for injury.

Here he has exposed the urinary bladder and is looking for any signs of problem

Sundance had no other abdominal organ trauma, so his rectus sheath and skin were sutured back together.

Here is the 7 inch incision in his abdomen after it has been sutured closed. These sutures will be removed in 7-10 days.

At this point in the procedure Sundance was given a pain injection and monitored carefully by our nursing team. He went home the next day and eventually made a full recovery. He was lucky this time, and certainly used up more than one of his nine lives!

Necropsy Photos

To give you a better understanding of anatomy we have some photos taken at necropsy of a diaphragmatic hernia on a pet that did not make it.

 

This thin, fan shaped, and very strong muscle is the diaphragm. The front side of this muscle is facing the abdomen. On the right side of this muscle is the thorax (chest). You can see the reddish colored liver at the bottom of the picture.

This one has been torn at the bottom

This liver has gone through a torn diaphragm and is now in the thorax. The vertical white line on the left is where the diaphragm was. To the left of this white line is the abdomen, where the liver normal resides. To the right of this line is the thorax, which now contains the liver, when it should not.

When you pull the liver away you can see the heart and lungs

When abdominal organs are in the thorax they take up space and prevent the lungs from expanding. The lungs might also be bruised, called pulmonary contusion.

The darker areas of these lung lobes have pulmonary contusion

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