By Dr. Lenard M Hughes
I have been asked to write a series of articles about the research I am doing with a wide range of reptiles. I established a non-profit corporation, Reptile Kingdom Inc, in 2018 to set up a facility to contribute to the knowledge of medical and surgical care of reptiles and their husbandry. My interest in reptiles began very early in my life. My father brought me my first snake at the age of 6 months (my age not the snake’s). I grew up in a family with a strong emphasis on the scientific study of nature. I majored in chemistry in my undergraduate years, attended graduate school in biological sciences and then attended medical school while taking many courses in veterinary sciences. My main interest has always been in surgery and especially congenital anomalies. I completed my residencies in general surgery, urology and fellowship in pediatric surgery. The field of surgery encompasses in depth knowledge of adequate nutrition and metabolism so an animal or human can tolerate the stress of surgery. Otherwise the outcome can be dismal. There are many conditions that occur in children developmentally that illustrate just how closely related we are to the animal kingdom. Just for example, there are human children born rarely with cloacas that must be repaired, a very complex surgery.
As an adult, while still in residency I purchased a baby green iguana and my collection of these beautiful creatures gradually escalated until now where I own about 75 reptiles at my sanctuary, research facility, and sometimes rehabilitation center. Had I attended veterinary school, I would have completed a fellowship in reptile medicine, something very few veterinarians have ever accomplished, I’m not sure why, it could be they feel there is no money in treating reptiles or that most of them receive such minimal training of reptile diseases during their course of study. More and more of the population now have reptiles as pets, breed reptiles, or their livelihood depends on reptiles. So reptile health and well being is very important, not to mention they deserve better veterinary care.
I read the reptile literature avidly but find knowledge is very limited in many areas. There is much more work and research that needs to be done. The field of medical herpetology is in its infancy and needs many more dedicated individuals. I will attempt to share some of my knowledge and findings with the herp community and hopefully make life much better for reptiles. I have formal education in parasitology which is essential knowledge needed to care for these animals. I am able to identify the most common parasites of reptiles and am learning more about their treatment as time goes on, but that will be covered later in another article. One parasite that deserves mentioning is cryptosporidiosis which is lethal in most reptiles with no known treatment to date to eradicate the parasite, and most vets recommend euthanasia. That is one disease I am currently trying different treatment methods to at least control the parasite so your animal can live out their life.
One of the species that has really caught my attention is monitor lizards (though I have never seen a snake I did not like) and I have several tortoises that I love dearly. Monitor lizards are one of the most intelligent groups of reptiles next to crocodilians. They are a very interesting family of reptiles, with about 53 or more different species in the family Varanidae. They range in size from about 21 centimeters to about 3 – 4 meters in length. Their weights vary from a low of 17 grams to over 100 kilograms, as seen in Komodo dragons. They originate from various regions of Africa, Asia, and Australia. They are all insectivores or carnivores with the exception of one species that eats fruit. The first fossils of Varanid like reptiles were first present about 100 million years ago, so it is an older group that has lived on this planet for a long time.
Some of the species have been bred in captivity but there have been many problems breeding them. I mentor monitor owners that are having medical issues with their lizards and many of these problems are related to reproduction or metabolism. I, myself, had a 6 year old Savannah monitor that developed a liver tumor, she passed about 6 months later. A veterinarian did open surgery but did not have the skills to remove a large liver tumor, and the reptile pathologist was rather vague about what type of tumor, whether malignant or not. Another Black Throat Monitor that I purchased at the age of two years from someone else, had follicular stasis, which I will explain later. The lizard underwent surgery by a veterinarian to remove her ovaries, follicles and oviducts but died the next morning, I expect from too much blood loss and not receiving any fluids during her surgery: most veterinarians do not have the skill to start an intravenous line in a reptile because they usually require a cut down technique, and they do not seem to appreciate that reptiles also need fluids to support their cardiovascular system during a major surgery. Fluids can also be given subcutaneously or intracoelomic. I understand that the majority of veterinarians are mostly trained to treat dogs and cats, and a few call themselves exotic vets but have not completed the two year fellowship in reptile medicine or zoo medicine.
I receive many contacts from persons with monitor lizards that have taken their animals to an “exotic vet” and they just do not have a good understanding of the physiology and metabolism of these alien creatures. The majority of seriously ill reptiles die which is very sad and should not happen. Just for example the half life of an antibiotic in reptiles, that is the time that one dose remains in the bloodstream before another dose is needed, is exceptionally long as compared to mammals. A cephalosporin might need to be given 3-4 times per day in a mammal but only needs to be given once every 3 days in a reptile, due to totally different processing of the medication. The kidneys are more primitive in reptiles and the liver functions quite differently. All of these things need to be considered when giving an anesthetic agent, or you can easily kill the reptile. They do not metabolize the anesthetic agents like a mammal. I just recently have a friend who lost a beautiful, adult, female Nile monitor. An anesthetic was given to get a liver biopsy found to be hepatic lipidosis, but because the liver was impaired the lizard could not properly metabolize the anesthetic agent and died the following day. The amount of anesthetic could have been dramatically reduced. This should have been a treatable illness.
Pre-ovulatory follicular stasis occurs quite frequently in female monitor lizards in captivity. To try and explain what this is, female lizards form ovarian follicles followed by ovulation or reabsorption. With follicular stasis, the developing follicles do not pass down the oviduct but remain attached to the ovaries. This can be the result for many reasons, things like poor nutrition, lack of activity, the fact that reptiles in captivity are bred throughout the year not just during their normal hormonal cycles. Even for other unknown reasons, like no male being present, or even low calcium levels in the female.
Signs of follicular stasis include restlessness, pacing, abdominal distension, anorexia, and later lethargy and dehydration. The best diagnostic technique is ultrasound. The best treatment is ovariectomy and I would recommend removal of the oviducts. If one plans to breed the animal you can give her a nest, supplemental calcium twice a day, and tube feed her if she does not eat on her own, another topic I can cover later. Oxytocin will not help. If her condition deteriorates it is vital to keep her warm, provide adequate hydration, something most vets do not think about, and prepare for surgery.
Hepatic lipidosis can also be lethal to your monitor. This is the result of fat accumulating in the liver. The cause of this is multifactorial but a high fat diet with lack of exercise and obesity are definitely high on the list. Female lizards are more susceptible especially if not bred because they accumulate fat and do not lose the fat through egg production. Animals in captivity do not have the opportunity to undergo periods of fasting like they would in the wild. Any lizard or other reptile in captivity should have their weight recorded regularly, records kept to document any change in appetite, or a change in the stools. While on this subject I would highly recommend that accurate records be kept of each animal. I keep a book of all feedings or refusal to eat, weigh each animal at least every 2-3 months, record all sheds, and any changes in appetite or stool consistency. Again ultrasound is probably the best method to view the liver and a biopsy may be indicated if the liver is enlarged or any of the above findings are present.
I have tried to discuss several of the most lethal and more common diseases seen in monitor lizards. Of course, many reptile deaths are from poor husbandry and/or parasites. They also can get cancers and have metabolic disorders especially of calcium metabolism. I hope this is not overly technical to be useful to most reptile keepers. When you do consult a veterinarian to examine your reptile, you can be helpful by reminding him of some of the issues I have discussed but do it in a non-confrontational manner. I feel sure they want to help save your animal but reptile medicine is a very complex field and most vets simply do not have the time to read the literature except some of those at academic centers.
Be alert to any changes in your reptile’s activity, appetite, appearance and frequency of the stools, and in their level of responsiveness to you. They are like a very young child or human infant who can not describe where they feel bad. That is the type of patient I treated most of my life so reptiles are just another patient with the same challenges.
I’m looking forward to writing more medically related articles about reptile health. You can always let me know if there is a particular topic you are interested in learning about more in depth.
