Long Beach Animal Hospital Informational Articles

Iguana Bone Disease (NSHP, MBD)

The most common reptile brought to our hospital is the green iguana. The primary reason owners bring in their ill green iguana is because it has developed a disease called metabolic bone disease (MBD), also known as nutritional secondary hyperparathyroidism (NSHP), or just secondary hyperparathyroidism (SHP).

This Iggie decided he just wanted to hang out and drink our coffee

This big boy shows how much bigger they can get. Unfortunately, some of these male iguanas are this large because they were fed a diet too high in protein when they were young, which will affect their kidneys later in life. 

The main cause of this disease is poor husbandry, especially an inadequate diet. Unfortunately, the literature abounds with erroneous information on the precise needs of these creatures. This outdated and incorrect information continues to be propagated by individuals and organizations with good intentions but limited knowledge.

Iguanas are not the only reptile that encounters this problem. We find it in many types of chameleons, lizards, turtles, and tortoises. It does not occur in carnivorous reptiles like snakes and monitor lizards very often because of their lower requirement for UVB light, and the whole prey they consume provides a proper diet. In essence, they are carnivores, while the other reptiles are vegetarians.

In older reptiles this disease manifests itself as renal secondary hyperparathyroidism (RSHP) due to compromise of the kidneys. The symptoms are the same as NSHP.

Cause

This disease has many factors that work together in causing this condition. The primary reason iguanas develop this disease is due to a diet too low in calcium. More specifically, the ratio of calcium to phosphorous (usually the phosphorous is too high) in their diets is inadequate to promote growth and sustain normal physiological functions. As a result, they become very ill, and can even succumb to the disease.

Other factors that exacerbate the poor diet problem are common in most households that have iguanas. Inadequate exposure to direct sunlight (not through glass), not keeping the humidity at 90% and not keeping the temperature at 90 degrees F all add to the problem:

Sunlight of a specific ultraviolet frequency is needed to produce vitamin D3 by the iguana’s skin. This vitamin is needed for the absorption and utilization of calcium in the diet. No matter how much calcium there is in the diet, without this vitamin the calcium would not be be absorbed or utilized . This is why milk that we drink is fortified with vitamin D. Black Lights and other artificial ultraviolet lights are helpful, but they can not replace sunshine.

In order to maintain normal bodily functions (ability to digest food, fight infections, etc.) an iguana needs to maintain a high body temperature. Since they are reptiles, they maintain this temperature by absorbing the heat from their environment. They cannot produce enough internal body heat like birds and mammals can when placed in a cold environment. Also, the precursor to vitamin D needs to be at the proper temperature to be converted to the active form of the vitamin.

In the semi arid environment in some parts of the country (southern California for example), or the heat needed to warm homes in the winter, many iguanas live in a perpetual state of dehydration. This dramatically interferes with their physiology, and predisposes them to many problems.

This is a typical Iguana cage that is inadequate. There is no branch with leaves to bask on, no access to any sun, let alone through the glass, and inadequate humidity. The bowl of water does not give enough moisture, and the heat lamp that is present in the corner does not supply proper ambient heat. Putting dirt in the bottom of the cage is a good idea.

They type of caging and lighting needs to takin into account the unique physiological needs of each reptile species. For example, the UVB light source for lizards needs to be above the cage because only then can is stimulate their pineal gland, which regulates their daytime basking.

This is the pineal gland on the top and middle of the head of this iguana that is looking towards the left

Caging and husbandry also needs to take into account the feeding behavior of each reptile species. Some need the food in trees and vegetation, while others need food on the ground. Water bowels need to be at different sizes and depths to accommodate individual preferences.

All of this means that you need to fully understand the husbandry of the reptile species you are contemplating on having as pet if you want it to live a healthy life. Diseases like MBD are serious, life threatening, and lead to significant suffering that is not necessary.

Symptoms

Iguanas with this disease have many problems. Initially they might be sluggish, unable to life their trunks very high off the ground, and not able to walk well.

The bones might be swollen or soft. The jaw might be swollen (called lumpy jaw by some people) because nature is trying to bring in supporting tissue to make up for the lack of strength to the bones of the jaw. The same thing happens to the bones of the legs, and when the problem is severe enough, or has gone on long enough, the bones of the arms and legs can fracture (called a pathologic fracture) all by themselves.

Some of these iguanas will be unable to walk properly due to spinal cord damage, and many of them will be more susceptible to common infections because they are too weak to develop a proper immune response. As the bones of the jaw become weaker it becomes impossible to eat, further exacerbating the problem. In severe cases the blood calcium level becomes so low that tremors occur.

They might have distended abdomens and bones leading their owners to the erroneous conclusion that their pet is fat and sassy, and receiving an adequate diet. Growing iguanas and females laying eggs have a greater need for calcium and might be more prone to this problem.

A proper diet, with the proper Calcium:Phosphorous ratio, is needed for healthy eggs

Females with eggs might not have the strength to lay them. This picture is from a surgery to remove toxic eggs in an egg bound  iguana.

Lumpy jaw occurs when the body brings fibrous tissue to the area to stabilize the weak bones. A lump at the jaw can also be caused by an abscess.

The fold of skin on the side of this iguana is evidence of dehydration

This Iguana has such a low calcium level that the muscles are twitching. This is called tetany, and is a serious sign. The two most common causes of tetany in an Iguana are MBD and Kidney failure.

This Iggie is so weak it cannot move properly

Diagnosis

A diagnosis of NSHP is made based on history, physical exam findings, and radiography. The history might indicate a diet of iceberg lettuce, dog or cat food, or packaged iguana meal. Swelling of the jaw and legs, low body weight, weakness, dehydration, poor appetite, and lethargy all might be noted on physical exam.

X-rays (radiographs) are very helpful in the diagnosis. We assess all organs, especially the bones. 

This is the femur (thigh) bone of a healthy iguana. Compare it to the diseased one below.

This is the thinning (arrow) that occurs in this disease. In addition to poor bone strength, this iguana has an infection.

This iguana has a severe form of the disease. The spine is deformed which has interfered with the nervous system, so it is unable to walk or eat well. This creature is gravely ill. To let a creature deteriorate to this point is a crime.

An x-ray reveals the extent of the curvature problem to the spine

This is the radiograph of a normal iguana. Notice how straight the spine is and how strong the leg bones are.

Even though this is a problem of low calcium level, blood samples show normal calcium levels commonly. This is because the body is absorbing calcium from the bones. 

Kidney failure in iguanas can cause RSHP as explained earlier. When there is kidney failure, the blood panel might show the problem.

We had an indication this sick iguana had a kidney problem when we palpated the large kidneys in the abdomen (it’s actually called the coelomic cavity in reptiles). The kidneys are far back in the coelomic cavity compared to most other animals. 

radiograph show enlarged and calcified kidneys

The calcium and phosphorous are both very high, commonly seen in kidney failure

Getting blood on a reptile all depends on the species and their size.

On iggie’s we take it from the underside of the tail

On tortoises we take it from the jugular vein

On snakes we take it directly from the heart. The real challenge is finding the heart!

It is obvious in this picture- you do see it, don’t you?

If you need help we can pull out the ultrasound to find it

Good job, you found it!

Treatment

Iguanas that are diagnosed with NSHP are usually very ill and often need to be hospitalized in a special warm and quiet room. During hospitalization they are given fluids to correct dehydration, a special liquid diet, injections of vitamin D3, injections of calcium, oral calcium, and antibiotics if they have an infection.

After they are stabilized in the hospital they are sent home with calcium supplements, antibiotics if needed, and their dietary deficiency is corrected. They need to return weekly for at least several weeks for vitamin D3 injections and calcitonin injections.

Those that have pathologic fractures are splinted. A typical splint applied when both rear legs have pathological fractures

An x-ray of this splint shows the padded paper clips that are used for support

This different case was referred to us. The splints on these front legs are inadequate, as evidenced by the displacement of the fractured ends.

We performed surgery in order to correct this problem. These pins will be removed in 1-2 months.

This iggie shows how the femur bones look after a successful treatment to stabilize fractures

 

This disease also occurs in tortoises. The shell is soft due to inadequate nutrition.

The lower arrows point to severely diseased and fractured rear legs (femurs) of this CDT. This upper arrow points to an impaction in the intestines, although a bladder stone can look like this also. 

It was a three person job to brace the jaw and prevent it from spontaneously fracturing (called a pathologic fracture)


This is also a serious problem in chameleons. Click on the picture above to learn a whole lot more, and watch videos of their eyes moving independently!

Prevention

It must be fully understood that iguanas are ectothermic animals. This means they are highly dependent on their environment for their normal physiological functions, much more so than birds and mammals. They come from Central america where the temperature and humidity are consistent- 90% humidity and 90 degrees F. In addition, they bask in the direct sun many hours each day. If these conditions cannot be replicated, then these animals should not be kept in captivity. Ignorance of their needs is no excuse.

Their diet should consist heavily of dark green leafy vegetables in order to have the proper ratio of calcium to phosphorous. Contrary to what you may read elsewhere, these animals are not omnivores, they are strictly vegetarians, even when they are young. Therefore, high protein diets (dog food, cat food, protein supplements) are not to be fed to them. These high protein diets will cause them to grow bigger and faster, but will also cause their kidneys to fail. Vitamin supplements that contain calcium should be given weekly.

The following list describes would should and should not be fed. A combination of several items from the “Should Be Fed List” need to be fed, not just one or two items. For small iguana’s it is helpful to dice up your vegetables into very small pieces so that they don’t eat only a few items.

Foods That Should Be Fed

 

Collared Greens

Mustard Greens

Green Leaf

Red Leaf

Butter leaf

Dandelion Greens

Mango

Papaya

Broccoli

Non toxic flowers

Foods That Should Not Be Fed

 

Dog Food

Cat Food

Rodents

Eggs

Iceberg

Lettuce

Pizza

Meat

Insects

Prognosis

This disease is correctable and preventable. If a pet iguana is brought to us in an advanced state of the disease then the prognosis is not good. Otherwise, we are able to return a large percent of them to relative normalcy if our full treatment regimen is followed. After the immediate problem is corrected it is mandatory to provide the optimum environment for their proper quality of life.

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Iguana Bladder Stones

Common Green Iguana’s occasionally have a problem with bladder stones (the medical term for bladder stone is urolithiasis). It is difficult to determine exactly why they have this problem. Just like in tortoises, the bladder stone can be very large. In addition to learning about the surgical removal of a bladder stone in an Iguana in this page, we also have pages that show a bladder stone removal in a dog and a tortoise. They also show pictures for interesting surgeries to remove them.

At the end of this page we have a short movie on the removal of a bladder stone from an iguana.

Graphic surgical photos on this page.


 

Symptoms

In dogs and cats there are several clues as to when a pet has a bladder stone. These include straining to urinate, blood in the urine, and lethargy. In reptiles the symptoms are not so clear cut since they don’t have the same habits as mammals and they easily hide symptoms of disease. Sometimes they don’t have any symptoms, in which case the diagnosis is made accidentally while looking for other problems. In general, the symptoms of a bladder stone in an Iguana might include lethargy and a poor appetite.

Diagnosis

 

A diagnosis of a bladder stone in reptiles is usually made by taking a radiograph.

This is the radiograph of Elvis, an Iguana with a very large bladder stone that is easily visualized as the large and circular white object

Another view gives some additional perspective as to the size. It has probably been there for years to progress to this size.

 

Treatment

The treatment of choice for this bladder stone is surgery. It takes about an 90 minutes from start to finish.

Its a meticulous surgery that requires a very gentle touch to an inflamed and sensitive bladder. It is performed under sterile conditions to minimize any chance of infection.

Here is Dr. Ridgeway working on his skin incision at the start of the procedure.

 

Anesthesia is initially induced with a face mask. Sometimes Iguana’s are given a tranquilizer before we given them anesthetic via the face mask. The anesthetic works rapidly, as long as they don’t hold their breath!

When she has relaxed enough, a special tube (called an endotracheal tube) is placed in the windpipe. This tube allows us to inflate the lungs and supply adequate amounts of oxygen and anesthetic.

The endotracheal tube is gently passed into the opening to the windpipe. This opening is at the back of the tongue, and can be difficult to visualize due to the fleshy tongue.

All of our surgeries are performed under sterile conditions. The skin is cleansed numerous times with a special antiseptic agent. The area is covered with a sterile drape and the surgeon uses sterile equipment for the duration of the procedure.

Iggie-AbdominalPrep

While our nurse prepares our patient our doctor is doing the same cleansing of his hands.

_D2A8630

This is a major abdominal surgery, so our surgeon is fully gowned and masked

Rabbit-femurfx-3

A scalpel blade is used to nick the skin enabling us to use a special scissors to extend the incision. The incision is around 6 inches long in order to have an opening large enough to remove this stone from the coelomic (the reptile version of abdominal) cavity.

Great care must be taken when extending the incision with the scissors. Immediately below the skin is a large vein that must be avoided. You can see it here as the dark blue object running horizontally.

The bladder is then localized and brought out through the incision. It is carefully assessed to determine the correct location to place sutures and to make an incision. Notice the large number of blood vessels that cover the surface of the bladder.The bladders wall is quite thin and can easily tear, especially when inflamed because of the large stone.

The opening is draped with moistened sterile gauze to minimize contamination and keep the bladder moist. A small suture (called a stay suture) is placed at each end of the bladder to keep the bladder in position and to minimize handling during manipulation of the stone. The arrow is pointing to the suture as it is being placed at one end.

When the bladder has been properly stabilized an incision is made at an area where there is minimal blood supply. The incision is made just large enough to squeeze out the stone.

The stone is carefully squeezed out of the bladder. You can get an idea of its size in relation to Dr. Ridgeway’s hands. It is hard to imagine what type of pain this must be causing.

Internal organs like the bladder have to be kept continually moist when they are not in their usual position inside the body cavity. Here we are moistening the bladder with sterile saline just prior to suturing.

The bladder is sutured with a special suture material that will slowly dissolve over several months. This suture is very strong and will hold the cut edges together during the time the healing is progressing.

Reptile skin is sutured differently than mammalian and avian skin. For reptile skin to heal properly the edges must be “everted”. Within a month these sutures are taken out and within three months the scales are back to normal.

Iggie-AbdominalSutures

Here is Elvis immediately after surgery and just prior to her pain injection. She is being kept warm to aid in her recovery. She went home the next day and is healing fine. We will be monitoring her condition to help prevent the recurrence of this stone.

Click on the link below to see a video of bladder stone removal in an iguana.  The sound you hear at the beginning and end is the Doppler monitoring the heart rate.

Iggie Bladder Stone Surgery

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Gecko Tail Amputation

It is not uncommon for reptiles to be presented with trauma to either the tail or one of the digits of the feet. In most cases they are brought in by their owners after the disease is well established and it is impossible to salvage the traumatized area. This page shows a case in a Leopard Gecko (do you recognize him? His picture is at the entrance to the reptile section).

Gecko-tailamputation

Treatment

This is the tail upon presentation to our office. Initially we treated it with antibiotics to save it but the problem progressed and we were worried about infection spreading to the rest of the body.

Gecko-tailamputation-2

We perform preanesthetic blood panels in reptiles just like in any species. There is a vein in the tail that gives us the amount of blood we need with minimal trauma to the animal, especially when the tail is infected. In this picture we are taking a blood sample from this vein, even though it might look like we are taking the blood sample from its abdomen.

Gecko-tailamputation-3

The amputation goes rapidly because there is minimal blood supply to the tip of the tail due to the infection.

Gecko-tailamputation-4

Before we begin the process of suturing the opening we make sure we have removed all of the infected tail and there is adequate blood supply to allow the skin edges to heal.

Gecko-tailamputation-5

These stitches will be kept in for 3-4 weeks because reptile skin heals much slower than mammal skin.

Gecko-tailamputation-6

Our little friend is waking up from anesthesia. He feels lots better now that the infected tail is gone.

This would have been an ideal surgery to perform with our laser.  Click here to learn more about laser surgery and to see pictures of its use.

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Reptile X-rays

In this fun page you get an opportunity to guess the species of reptile by looking at a radiograph.

Eggs in a water dragon

Liz Candova Preg water dragon

Snake head

snake head closeup

Snake body (impacted with feces)

Radiographs-Snake

Monitore lizard filled with abdomen filled with fluid

Radiographs-MonitorAscites

Urinary bladder stone in an Iguana

Radiographs-Iggiestone

Radiographs-Iggiestone-2

Splint for Iggie with broken legs due to NSHP

Radiographs-IggieNSHP

Eggs in chameleon

"Monkey" Boscon 2/4/98

"Monkey" Boscon 2/4/98

Normal anatomy of chameleon

Radiographs-Chameleon

Bearded dragon

Radiographs-bearded

Frog (amphibian) distended with fluid.

27176 Chunky Glose Ascites

Chuckwalla urinary bladder stone

Chuckwalla

Chuckwalla-2

This is the forearm and foot of a California Desert Tortoise

 


This tortoise is filled with eggs

 


Can you guess the species just by looking at the x-ray? The answers are at the end, just click on the number. Good luck!

#1


#2

 


#3

 


#4

 


#5

 


#6

 


#7

Answer for #1

#1- Frilled Lizard

Answer for #2

#2- Green Iguana

Answer for #3

#3- Monitor Lizard

Answer for #4

#4- Blue Tongue Skink

Answer for #5

#5- Soft Shell Turtle

Answer for #6

#6- Tegu

Answer for #7

#7- Veiled Chameleon

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Reptile Feeding Tube

We will routinely use feeding tubes in tortoises that are not eating well even though some reptiles can go many days without eating. Sometimes they are not eating due to a traumatic injury or internal illness. Other times they might be recovering from surgery, either a bladder stone removal, or a removal of their eggs. This section will show you how we put a feeding tube into a California Desert Tortoise (CDT).

Graphic photos on this page.

Tube Placement

This is what it looks like inside of the mouth of a CDT. They have a fleshy tongue and horny plates for teeth. Once it is in place the feeding tube will be bypassing this oral cavity and food that is administered through the tube will go directly into the esophagus.

In reptiles the esophagus is found towards the right side of the neck. This is also true in birds, and the opposite of mammals. In this picture the tortoise is on its back and its head is towards the left. A hemostat has been passed through its oral cavity into the esophagus at the point where the feeding tube will be inserted. The arrow points to the hemostat as it bulges just under the skin.

CDT-FeedingTube1

A nick is made in the skin with a scalpel blade right over the bulge. This allows the hemostat to gently advance through the wall of the esophagus and the skin to the outside.

CDT-FeedingTube2

The hemostat is used to grab the tip of the feeding tube. The hemostat and feeding tube will be pulled back out through the oral cavity. It is not possible to just pass the tube down into the esophagus at this point in the procedure, it must first come out through the mouth and then be passed down into the esophagus.

CDT-FeedingTube3

This view shows several things. Under the tip of the orange feeding tube you can see the breathing tube we use to administer anesthesia. You can also see the orange feeding tube passing into the esophagus in the upper right part of the picture and out through the mouth. We have taken off the hemostat that was used to pull it through so you can have better visualization. We will replace the hemostat on the tip of the tube and gently place the tip of the tube past the original incision we made in the esophagus.

CDT-FeedingTube4

This close-up shows the feeding tube properly in place, having been passed down the esophagus to a previously measured point. This technique of pulling the feeding tube from the esophagus, out through the mouth, and then back down the esophagus, is called retrograde placement.

CDT-FeedingTube5

The tube is sutured at its insertion point into the esophagus and the remainder of the tube is taped to the top of the shell. The tube can be used to administer food, water, and medication for an extended period of time.

This closeup shows how we secure the tube

CDT-FeedingTube

CDT-FeedingTube6

This x-ray of the tortoise on its back shows how the tub looks like on the inside. The arrow on the left actually shows the part of the tube that is taped to the top of the shell. The arrow towards the right shows the tube in the esophagus.

We also put feeding tubes in mammals, especially cats.

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