The disease process causes severe necrotizing colitis, hepatic and pancreatic necrosis with associated granulomas.
Clinical signs occur approximately 2–10 weeks prior to death.
SIGNALMENT/HISTORY
All ages can be affected. Animals consistently kept in temperatures between 25–33 degrees C.
Carnivorous chelonians appear to be more susceptible versus herbivorous chelonians.
Herbivorous chelonians can be asymptomatic carriers.
CLINICAL PRESENTATION
Anorexia
Diarrhea
Dehydration
Weight loss
Bloody and mucoid stools
Hardening of the large intestinal tract that can be palpated.
Intussusception
Vomiting
Sudden death
RISK FACTORS
Husbandry
Improper husbandry and hygiene, diarrhea, housed with infected animals, decreased immune status, temperatures held between 25 and 33 degrees C.
Invertebrates (i.e., roaches and flies) act as mechanical vectors.
Others
N/A
DIFFERENTIAL DIAGNOSIS
Salmonellosis
GI helminths
DIAGNOSTICS
Microscopic evaluation of fresh fecal material to visualize trophozoites and cysts.
Trophozoites may be seen in fresh fecal but die rapidly within 20–30 minutes once outside the host.
SAF technique can be used for better visualization.
Fecal/cysts can be placed within a petri dish with water and trophozoites will emerge from the dissolved envelope within several hours.
Immunohistochemistry with E. invadens poly clonal antibody is developed for snakes.
Polymerase chain reaction assays can be used to distinguish species of Entamoeba.
PATHOLOGICAL FINDINGS
Gross changes include thickening, edema, erosions, ulcers, and diphtheritic membranes of the large intestine.
Liver abscesses may also be seen.
Histologically, the primary finding is fibrinonecrotic colitis.
APPROPRIATE HEALTH CARE
N/A
NUTRITIONAL SUPPORT
Nutritional supplementation may be indicated if diarrhea, dehydration is severe.
CLIENT EDUCATION/HUSBANDRY RECOMMENDATIONS
Practice proper hygiene
Wash fruits and vegetables before being fed.
Do not house infected individuals with non‐infected chelonians.
DRUG(S) OF CHOICE
Metronidazole 25 mg/kg PO q24h for 5–7 days
PRECAUTIONS/INTERACTIONS
N/A
PATIENT MONITORING
Monitor for weight gain
Take fecal samples
EXPECTED COURSE AND PROGNOSIS
Good
COMMENTS
E. invadens in culture, dies at 37 degrees C, so can raise the temperature to 37 degrees C if it is within the animal’s preferred optimum temperature range.
E. histolytica and E. dispar, which are found in humans GI tracts, are morphologically similar to E. invadens but are considered to be non‐pathogenic.
ZOONOTIC POTENTIAL Unknown
SYNONYMS Amebiasis
ABBREVIATIONS
GI = gastrointestinal
SAF = Sodium acetate acetic acid formalin
INTERNET RESOURCES
de Cardenas C. Amebiasis in Reptiles. PetMD, October 1, 2008. www.petmd.com/reptile/conditions/digestive/c_rp_amebiasis• Amebiasis in Snakes. Wag! 2020. https://wagwalking.com/reptile/condition/amebiasis‐in‐snakes
