• Cause: Eimeria spp, Isospora spp, Caryospora spp, Choleoeimeria spp, Sarcocystis spp and Cryptosporidium spp.
• Signs: diarrhea, anorexia, weight loss, failure to gain weight.
• Diagnosis: fecal flotation, direct smear.
• Treatment: coccidia have a direct life cycle, and sulfonamides are the preferred treatment.
• Prognosis: generally good.

Overview

• Coccidia are intracellular protozoan parasites that usually have a direct lifecycle.
• A number of coccidian parasites are found in reptiles but their pathogenicity is variable.
• Pathogenicity is dependent on the species, host and the level of parasitism.
• Isospora, Eimeria, Caryospora, Choleoeimeria, Sarcocystis and Cryptosporidium are most commonly seen.
• Isospora amphiboluri is the most common species seen in clinical practice, particularly in the inland bearded dragon (Pogona vitticeps) and is usually non-pathogenic.
• Damage to the intestinal mucosa leads to weight loss, dehydration, secondary infections, renal disease and death.
• Intranuclear coccidiosis is a highly pathogenic emerging disease of chelonia.

Intranuclear coccidiosis

• Intranuclear coccidiosis is an emerging disease of chelonians that affects a wide range of species.
• The coccidian parasite has an intranuclear developmental stage, although details of its complete life cycle are not known.
• The organism has yet to be properly identified but it is likely related to Eimeria arnyi.
• Cells of multiple organs can be affected.
• Signs: rhinosinusitis, oronasal fistulae, lethargy, rapid weight loss, open-mouth breathing and swollen vent. The degree and severity of clinical signs depend on chronicity and which organs are affected. There may be weight gain associated with fluid retention and ascites. Most animals presented with clinical disease succumb to the illness.
• Diagnosis: intranuclear coccidiosis in the lungs has been reported in chelonia by biopsy, although a polymerase chain reaction (PCR) test has been developed. Renal or pancreatic biopsy yield the highest chance of positive samples.
• Prognosis: post mortem diagnosis is based on the histopathologic finding of intranuclear developing stages in multiple organs or by PCR testing; antemortem samples (cloacal/choanal/conjunctival swabs) can be tested via PCR.
• Treatment: remains unrewarding; however, there is anecdotal evidence that treatment of asymptomatic positive animals with toltrazuril may halt disease progression.
• Prognosis: generally very guarded to poor. Morbidity and mortality is high, but some animals may recover and become carriers. Recrudescence has also been observed.

Presenting signs

• Anorexia Anorexia.
• Lethargy.
• Diarrhea.
• Hematochezia.

Acute presentation

• Severe cases may be dehydrated and collapsed.

Age predisposition

• Many adult lizards with coccidiosis appear to be asymptomatic carriers, but neonates and juveniles with coccidiosis are more likely to be clinically diseased.
• Coccidiosis can cause death in small or young lizards if undetected and untreated.
• In young bearded dragons, coccidiosis may be associated with adenoviral infection.

Breed/Species predisposition

• Coccidiosis is a common finding in captive snakes and lizards, particularly bearded dragons (Pogona vitticeps) and leopard geckos (Eublepharis macularius).
• In wild snakes, coccidiosis is a self-limiting infection, but in captivity coccidia can cause severe illness, and in young snakes or smaller species death may result.

Special risks

• These animals may be dehydrated or generally dibilitated.