Tritrichomonas foetus infections in surveyed pet cats.

Tritrichomonas foetus is the causative agent of feline trichomoniasis, a large-bowel disease resulting in chronic diarrhea. Feline trichomoniasis has been reported in cats of both pure and mixed breeds and in both males and females. In order to estimate the prevalence of trichomoniasis in the pet cat population, we requested fecal samples, via veterinarians throughout the United States, from cats with or without clinical signs of trichomoniasis. Of the 173 feline fecal samples received from veterinarians, 17 were culture and PCR positive for T. foetus. Our results suggested no correlation between breed or sex and infection with T. foetus. All cats that were infected with T. foetus had diarrhea at the time the fecal sample was taken. Other enteric pathogens were present in nine of the 17 positive cats. Our results support that trichomoniasis is a disease of younger male and female cats of all breeds.

Experimental infection of cats (Felis catus) with Tritrichomonas foetus isolated from cattle.

Tritrichomonas foetus is recognized as the causative agent of venereal trichomoniasis in cattle. It is characterized by embryonic and early fetal death and post-coital pyometra, and feline trichomoniasis, manifest as chronic, large bowel diarrhea. Many of the infected cats are less than 2 years old and specific routes of transmission remain unknown. We recently demonstrated that feline isolates of T. foetus can successfully infect heifers, resulting in pathologic changes similar, but not identical to those previously reported as representative of bovine trichomoniasis. In this study, we experimentally infected six cats less than 1 year of age with a bovine (D-1) isolate of T. foetus and one cat with a feline (AUTf-1) isolate of T. foetus. Within 2 weeks, the cat infected with the feline (AUTf-1) isolate was culture positive for trichomonads in weekly fecal samples. At the end of 5 weeks, only one cat infected with the bovine (D-1) isolate was fecal culture positive for trichomonads. At necropsy, the intestine of each cat was removed and divided into five sections (ileum, cecum, anterior, medial and posterior colon). Contents from each section were collected and cultured. The cat infected with the feline (AUTf-1) isolate was culture positive in the ileum, cecum, medial and posterior colon. Two cats infected with the bovine (D-1) isolate were culture positive in the cecum only. Additionally, each intestinal section was submitted to a pathologist for histopathological examination. The combined results indicate that there are demonstrable differences between the feline (AUTf-1) and bovine (D-1) isolates regarding their infectivity in cats.