EDUCATION/HUSBANDRY RECOMMENDATIONS
Remove and isolate sick individuals and reduce stress by providing optimal living conditions and hygiene.
Thoroughly clean the animal’s cage to reduce environmental contamination of oocysts.
Ensure that quarantine protocols have been adopted for all new arrivals; during quarantine, all animals should undergo repeated clinical and fecal examinations.
DRUG(S) OF CHOICE
Because Eimeriaspp. are rarely pathogenic, prophylactic therapy or treatment should not be based on the identification of Eimeriaspp. alone, to avoid development of resistance.
Treatment should only be performed after an Eimeriasp. has been confirmed to be causing clinical disease.
Ponazuril 30 mg/kg PO q48h for 2 treatments, or 30 mg/kg PO q24h for 4 treatments, then repeat for 2–4 treatments 2 weeks apart.
Toltrazuril 15 mg/kg PO q48h for 30 days
Sulfadimethoxine 50 mg/kg q24h for 21 days
Trimethoprim‐sulfa 30 mg/kg daily for 5 days then q48h until the coccidia are eliminated.
PRECAUTIONS/INTERACTIONS
Sulfa drugs are known to be nephrotoxic and care should be taken with their use, particularly in dehydrated or severely compromised individuals.
PATIENT MONITORING
Repeat fecal examination at monthly intervals.
EXPECTED COURSE AND PROGNOSIS
Treatment may have variable efficacy as many protozoa are resistant to a range of anti‐coccidial medication.
Prognosis is good to guarded and is determined primarily by the state of the animal at initial presentation and the presence or absence of concurrent disease.
COMMENTS
N/A
ZOONOTIC POTENTIAL
High host‐specificity. No known zoonotic risk with any Eimeria species.
SYNONYMS
N/A
ABBREVIATIONS
GI = gastrointestinal
K2Cr2O7 = potassium dichromate
PCR = polymerase chain reaction
w/v = weight by volume
Suggested Reading
1 Gibbons PM. Advances in reptile clinical therapeutics. J Exot Pet Med 2014;23(1):21–38.
2 Helke KL, Cooper TK, Mankowski JL, Poynton SL. Disseminated visceral coccidi-
3 osis in Indo‐gangetic flap‐shelled turtles, Lissemys punctata andersonii. J Wildl Dis 2006;42(4):788–796.
4 Jacobson ER. Parasites and parasitic diseases of reptiles. In: Jacobson ER, ed. Infectious Diseases and Pathology of Reptiles: Color Atlas and Text. Boca Raton, FL: CRC Press; 2007:571–665.
5 Scullion FT, Scullion MG. Gastrointestinal protozoal diseases in reptiles. J Exot Pet Med 2009;18(4):266–278.
6 Vetterling JM, Widmer EA. Eimeria cascabeli sp. n. (Eimeriidae, Sporozoa) from rattlesnakes, with a review of the species of Eimeria from snakes. J Parasitol 1968;54(3):569–576.
Author T. Franciscus Scheelings, BVSc, MVSc, PhD, MANCVSc (Wildlife Health), DECZM (Herpetology)
Entamoeba
DEFINITION/OVERVIEW
Entamoeba are characterized into two groupings based on morphology. The two groupings are based on the number of nuclei present. Entamoeba spp. in the group containing four nuclei are considered to be pathogenic and the main concern for reptilian species. Entamoeba spp. in the group containing eight nuclei are considered to be noninvasive. E. invadens is the most common pathogenic species seen in reptiles and has been known to cause significant mortality. Virulence can differ between strains of E. invadens; infectious cysts are 11–20.2 μm with four nuclei and a small central karyosome. Trophozoites are 17.5–50 μm in length (average 36.18 μm), 10–25 μm (average 12 μm) in width and average diameter of 24.1 μm. Trophozoites also possess a single nuclei with a large central karysome that is 5–7.5 μm (average 5.65 μm) in diameter.
ETIOLOGY/PATHOPHYSIOLOGY
E. invadens has a direct life cycle and transmission is through the fecal–oral route.
Cysts are ingested and then undergo excystation in the intestinal tract.
In chelonians, cyst production occurs by cell division and one metacystic form gives rise to eight amoebas.
E. invadens mainly inhabits the small and large intestines but can affect other adjacent organs, including the liver, kidneys, pancreas, and lungs via systemic circulation.
The motile feeding trophozoite can also encyst and then be passed through the host’s GI tract and out in the feces.
Trophozoites undergo encystation in which infective cysts are formed and then excreted in feces.
Cysts can remain infective for 14+ days at temperatures of 8 degrees C and several days at 37 degrees C.
It was first considered that chelonians were only carriers and E. invadens were commensal parasites, but there is sufficient evidence that the parasite can affect and cause mortality in all chelonians, including
