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Health and Safety Series: Cryptosporidium

Health and Safety Series: Cryptosporidium


This is an article I found on The links below no longer work but I will leave them there along with the other attribution. Crypto is a serious illness in reptiles caused by a protozoan. Crypto is highly infectious and almost always fatal. Western hognose and leopard gecko collections are at high risk of contamination through improper quarantine or hygiene procedures. The original article follows:


By Ryan Centini

What is cryptosporidiosis? Cryptosporidium is a internal protozoal parasite which is a type of coccidia. 

Can humans or other animals get cryptosporidiosis from reptiles? There are eight different species of Cryptosporidium. C. serpentis is the one that affects reptiles and seems only to effect reptiles. C. parvum affects mammals and is the only one known to affect humans. C. parvum can infect suckling mice a reptile that ate a mouse infected with C. parvum although it would not be affected by it, it could pass the oocysts in its feces and under these circumstances could infect a human. However this would really be getting C. parvum from a mouse not C. serpintis from a reptile. 

What reptiles can get cryptosporidium? It has been reported in all families of reptiles except crocodilians. Some species seem to be at higher risk of developing the disease than others; cornsnakes, eastern indigo snakes, pine-gopher snakes, (especially albino cornsnakes and pine-gopher snakes), emerald tree boas, boa constrictors, as well as rock rattlesnakes, monocled cobras, and death adders (but I hope these last three are not kept as pets!). Snakes in general seem to be at higher risk than other reptiles. In lizards it has been most commonly seen in Gila monsters, geckoes (especially leopard geckoes), chameleons, monitors, and iguanas. Cryptosporidium has been found in several species of turtles and tortoises. However it does not seem to cause disease in them, they may just be carriers of it. They can transmit it to snakes and lizards though. This is just one good example of why different species of reptiles should not be housed together. 

How is Cryptosporidium transmitted? Cryptosporium oocysts are shed in the feces and they are found on regurgitated food. These oocysts can then get on cages, bags, cleaning instruments, water bowls, cage decorations, in the water, and hands. And transmitted to reptiles in other cages. The oocysts can survive for several months in the right conditions (with the fecal matter or with moisture and low temperatures) and are hard to kill (see prevention below). Cryptosporidiosis should be considered as highly contagious and the highest standards in sanitation should be exercised.

What are the signs of cryptosporidiosis?
 In snakes cryptosporidium is mostly found in the stomach and causes weight loss, regurgitation, and in the later stages gastric hypertrophy (thickening of the stomach wall). In lizards it usually found in the intestines. Where it causes diarrhea, weight loss, and anorexia. There is a report of Cryptosporidium in the kidneys of a iguana and a Parson’s chameleon and the salivary gland of a iguana. There are reports of reptiles that shed the organism but never developed any signs and of reptiles that developed signs but through supportive therapy got better. These seem to be the exception though and most die. There are several diseases that can cause these same signs so LET A VETERINARIAN MAKE THE DIAGNOSES. 

Is there a cure for cryptosporidiosis? There are several drugs that have been tried. A lot of them have caused a decrease in the number of oocysts and a few even seem to have stopped the shedding. But these result have been inconsistent. Reptiles that are positive for cryptosporidiosis should be strictly quarantined with separate cleaning instruments or be destroyed.

How is cryptosporidiosis diagnosed? There are a few methods one is to do a acid-fast test on the contents of a stomach wash (this is best done three days after a meal in snakes), the feces, or mucus from regurgitated food. An immunofluorescent antibody (IFA) on the feces. A enzyme-linked immunosorbent assay (ELISA) on the plasma. And a biopsy of the stomach lining this is the most invasive, but can yield good results. With any of these tests a negative does not mean the reptile does not have cryptosporidiosis it just means it was not in that sample. With three negatives you can reasonably sure the reptile does not have it.

Prevention. As mentioned before cryptospridium is very hard to kill. The only known disinfectant that can reasonably be used is household ammonia with 30 minutes of contact. It should only be used in a well-ventilated area. AMMONIA AND BLEACH SHOULD NEVER BE MIXED. A substrate that can be thrown out like newspaper should be used, cage decorations should be plastic so they can be sanitized, wood is difficult to sanitize so should not be used. 

Found on at Crypto.htm

Cryptosporidiosis in Snakes
Cryptosporidiosis is an increasingly diagnosed parasitic infection in reptile collections, particularly in snakes. The course of the disease is unusual since it tends to be self-limiting in immunocompetent bovines, canines, felines, and other species, but can be fatal in its reptilian host. The infection is often insidious in onset, causing irreversible pathological changes before physical signs develop. Clinically healthy, intermittent shedders may become symptomatic years after the parasite is first diagnosed in the animal. Additionally, the affected animal may die acutely, or the clinical disease may take up to two years before killing its host.

The life cycle of Cryptosporidium serpentis is thought to be similar to that of Cryptosporidium parvum,muris, and other species in mammals. Two types of infective stages are produced. The first is a thick-walled oocyst which contains four sporozoites. The oocysts are passed in the feces and remain infective in the environment for months, where they are extremely resistant to temperature extremes and disinfectants. These oocysts are responsible for both infections in new hosts as well as reinfection of the original host. The oocysts are ingested, and the four sporozoites are released. The second stage involves four sporozoites encased not in a thick wall, but rather in a single, thin membrane. This membrane ruptures after breaking out of a host cell, releasing the sporozoites and immediately reinfecting the host animal. In both stages, the sporozoites infect the microvillus border of the gastric glands, and in snakes, lesions are usually localized to the stomach.

The classic presentation of Cryptosporidium serpentis infection in the snake is an animal which regurgitates its meal within four days or less of ingestion. This regurgitation occurs because of decreased gastric lumen size and mucosal irritation. Since the diameter of the stomach has often increased, a noticeable swelling can be visualized and palpated in the mid-body region. The snake may

or may not be anorexic, depending^n how far the disease has progressed. Often, a mucoid diarrhea is noticed.

It is important to differentiate Cryptosporidiosis from other causes of regurgitation and gastritis. Suboptimal temperatures, inappropriate prey size, stress, and foreign body obstructions are other potential causes of regurgitation. Hibernation associated necrotizing gastroenteritis, parasitism from other protozoa and nematodes, viruses, Salmonella and other bacteria can all cause similar signs, but the gastric swelling is pathognomonic for Cryptosporidiosis.

In the living animal, Cryptosporidiosis can be diagnosed by gastric lavage,endoscopic gastric biopsy, fecal smears, and smears of mucous adhered to regurgitated prey items. Since oocysts are intermittently shed, it is recommended that multiple samples be taken. It is important to note that a negative result does not imply that the animal is not infected, only that oocysts may not be present in the particular sample. Acid fast staining is the preferred technique for cytology and fecal preparations, and is easily performed.

Gross lesions include gastric hyperplasia and fibrosis, a decreased diameter of the gastric lumen, and an increased overall diameter of the stomach. Often, the gastric mucosa will be edematous and the rugal folds thickened longitudinally. Additionally, petechial hemorrhage and focal areas of necrosis may be observed.

Histopathologically, the microvillus brush border becomes disrupted as new oocysts burst out of their host cells. The acid secreting cells that line the gastric pits become reduced in number. Mucous secreting cells are hyperplastic, and the mucosa atrophies while the submucosa and musculature becomes fibrotic.Leukocytes may be present in response to the inflammatory process, and the lamina propria may become edematous. The organisms are microscopically visible attached to the epithelial cells of the brush border microvilli. It is recommended that multiple samples of gastric tissue, taken at necropsy, be submitted for histopathology in order to improve the chances of recognizing the organism.

Currently, there is no evidence that Cryptosporidium serpentis is transmissible to humans or other mammals.

References available upon request.

-by David Kolins, Class of 1996

-Edited by M. Randy White, DVM,PhD

Found at

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