Reptile-Related Diseases and Health Issues

Fungal infections in reptiles usually develop as a result of damp conditions (which are the correct environment for most reptiles). Medicated antifungal sprays designed for reptiles or consultation with a specialist exotics vet may help.


Metabolic bone disease (MBD) is a very common illness in reptiles that are not provided with the right diet or husbandry (low calcium, high phosphate, low Vitamin D, and lack of UVB light). A fecal examination can help diagnose this illness.

Bacterial Infections

Cold-blooded reptiles frequently harbor gram negative bacteria as part of their normal flora. They are often opportunistic pathogens and may cause disease in conjunction with poor husbandry practices. For example, the anaerobic bacteria Peptostreptococcus and Aeromonas have been isolated from reptilian abscesses. Chlamydia pneumoniae can also cause granulomatous lesions in lizards, snakes and tortoises. This bacterium is also known to infect humans, leading to disease such as atherosclerosis and Alzheimer’s disease.

Salmonella infections can occur in humans who have eaten contaminated food prepared by or touched a reptile and then unintentionally ingested the bacteria (salmonellosis). Symptoms of this infection typically begin one to three days after exposure and include diarrhea, stomach cramps and fever. The bacterium can also enter the bloodstream, infecting the heart and joints. Salmonella is one of the most common causes of diarrheal illness in children and elderly adults. Salmonellosis can be fatal for young infants.

Fungal Infections

Fungal infections usually begin on the skin and can be treated with over-the-counter or prescription antifungal medications. But if the infection isn’t treated, it can spread to other parts of the body and cause sepsis. Fungi most often affect people with weakened immune systems. They can also infect the lungs, eyes, or liver and are more common among those who have received an organ transplant.

Reptiles can get systemic fungal infections that affect many parts of their body. They usually develop when a reptile is in suboptimal environmental conditions for a prolonged period of time. Examples of systemic mycoses include nannizziomycosis, ophidiomycosis, and chytridiomycosis.

Symptoms of nannizziomycosis include swelling, scabs, ulcers, and crusty or discolored scales on the reptile’s face. It can be hard to treat and can lead to a deadly complication known as septic shock. It is also important to understand that fungi are becoming resistant to the antibiotics used to treat them.

Intestinal Parasites

There are parasites that live in the intestines of reptiles. These include roundworms (nematodes) and protozoans. Roundworms can cause diarrhea. They are spread by eating contaminated food or water, person-to-person contact and through the bite of a mosquito. The most common roundworms that affect people are hookworms (Ascaris lumbricoides) and whipworms (Echinoparus spp).

Protozoans are one-celled organisms. They can’t be seen without a microscope and may live in the intestines or blood and tissues. Most often, they cause intestinal disorders such as diarrhea. The most serious protozoal pathogen that can affect reptiles is Entamoeba invadens, which can lead to a variety of symptoms including anorexia, weight loss, mucoidal or hemorrhagic diarrhea and death.

There are many medications that can be used to treat intestinal parasites. Your doctor will prescribe the medication that is best suited to your needs. It is important to follow the prescribed treatment closely to prevent the recurrence of parasites.

Protozoal Infections

A number of protozoal infections can affect reptiles. The genus Hexamita has been known to infect the kidneys and bladder of aquatic turtles (renal hexamitosis), and Chilomastix, Tritrichomonas and Diplomonad flagellates are commonly found in the intestine of salamanders, frogs and toads. Hexamita causes severe anemia by destroying the red blood cells of the host, whereas the other three genera cause intestinal tract diseases in reptiles.

Reptiles can also act as a definitive or intermediate host of hermaphroditic cestodes such as thorny-headed worms (acanthocephalans). These parasites are usually found in the stomach or intestine, and their presence is indicated by a dark, thick-shelled proglottid that does not float in fecal material.

Cryptosporidiosis, caused by a group of protozoans adapted to mammals but found infecting endemic New Zealand reptiles, has been linked to increasing disease morbidity and extinction risk in these species (Fey et al. 2019). Clinical signs include diarrhea, emaciation, anorexia and weight loss.

Respiratory Infections

Reptiles are susceptible to the same types of viral, fungal and bacterial respiratory infections as other animals. However, poor husbandry is a major predisposing factor both for the development of disease and its progression once present. This is because inadequate temperatures or humidity levels are the most common causes of infection, limiting the ability of the reptiles to mount an immune response against any invaders. Additionally, the reptiles’ unique anatomy often limits treatment options. Snakes have a single symmetric lung whilst lizards and crocodilians have two, leaving them more vulnerable to infection and more difficult to treat.

Many reptiles are infected with Salmonella which can cause a variety of symptoms including lack of appetite, diarrhea and septicemia. Some reptiles also carry atypical mycobacterium species which can lead to chronic wasting disease in wild, imported reptiles and are seen as visceral granulomas at necropsy in captive bred reptiles. These bacteria can also infect humans who can develop mycobacteriosis with symptoms ranging from mild inflammation, such as dermatitis to lymphadenitis and pulmonary disease similar to tuberculosis in immunosuppressed patients.

Prolapsed Organs

Prolapse is the downward displacement of pelvic organs, including herniation into the anal canal or vagina. Pelvic organ prolapse can be divided into anterior compartment prolapse (cystocele or bladder prolapse), uterine prolapse and posterior colon prolapse. The latter can also be further divided into rectal intussusception and rectocele.

Cloacal prolapse is common in reptiles and often results in the ingestion of food by the herniated tissue. It can also cause a lack of water intake leading to dehydration and malnutrition.

A veterinarian may gently push the prolapsed organ back into the cloaca to relieve pressure. They will also perform a full health assessment of the reptile, including husbandry review.

Identification of the prolapsed organ is often difficult, although longitudinal striations on a cloacal prolapse can help differentiate it from colon or oviduct prolapse. The use of hypertonic saline soaked cotton swabs or lubricant can help prevent further injury to the prolapsed organ and allow for a quicker diagnosis and treatment.