Fulminant Tritrichomonas foetus ‘feline genotype’ infection in a 3-month old kitten associated with viral co-infection

Laura Setyo, Shannon L. Donahoe, and Jan Šlapeta


Original article:


Tritrichomonas foetus is a microscopic single-celled flagellated protozoan parasite which mainly causes colitis (large bowel diarrhea) in young cats and kittens. A 3-month-old Bengal kitten showed severe T. foetus infection of the colon, cecum and ileum with concurrent feline enteric coronavirus (FCoV) and feline panleukopenia virus (FPV). The kitten had an 8-day history of vomiting, diarrhoea, failure to thrive and coughing prior to being presented to the University of Sydney Veterinary Teaching Hospital. Protozoa filling the lumen and crypts and occasional invading into lamina propria were identified within the affected colon and confirmed by PCR as T. foetus‘feline genotype’. FCoV and FPV co-infection were also identified from fecal samples of the kitten via PCR. Immunosuppression caused by FPV may play a role in the unprecedented T. foetus infection intensity observed histologically.

Gastrointestinal pathology in a cat co-infected with Tritrichomonas foetus, feline enteric coronavirus (FCoV) and feline panleukopenia virus (FPV). (A) Cross-section of the colon with marked protozoal (T. foetus) luminal infiltrate (arrows). ( B) Numerous teardrop-shaped T. foetus overlying the mucosal luminal surface of a crypt of Lieberkühn in the colon. (C) T. foetus (arrow) in the cross-section of the crypts of the colon. (D) Crypt abscesses containing cellular and karyorrhectic debris and T. foetus (arrows) in the colon. Note the invading T. foetus in the lamina propria (arrow outlines). (E) Severe attenuation of the superficial epithelium of the small intestinal of the cat PCR positive for FCoV and FPV. H&E. (Virtual Slide for Virtual Microscopy: VM05606).