Molecular detection and pathology of cytauxzoonosis in captive royal Bengal tiger

Cytauxzoonosis, a tick-borne, feline hemoprotozoan disease caused by Cytauxzoon felis. In the present study, cytauxzoo- nosis was diagnosed in a 12-year-old male Royal Bengal tiger (Panthera tigris tigris). The tiger was presented with a history of anorexia and lethargy. It was severely dehydrated with a temperature of 104.2°F. On the following day, icterus developed and the clinical symptoms progressed to recumbency, coma and the animal subsequently succumbed. Hematologic examination performed shortly before death indicated icteric plasma, severe thrombocytopenia, mild anemia, hematuria and circulating red blood corpuscles demonstrated Cytauxzoon felis. Gross necropsy findings comprised of generalized icterus, generalized petechial and ecchymotic hemorrhages along with splenomegaly and large areas of necrosis on lung lobes with congestion. Liver was enlarged with evidence of subcapsular necrosis. Macrophages containing developmental schizont stages of C. felis as observed in histopathology partially occluded blood vessels of vital organs of lungs, spleen and liver obstructing the blood flow thereby leading to tissue necrosis that might be one of the pathogenic effects of the Cytauxzoon infection in tigers.