Tritrichomonas foetus infection in cats with diarrhea from densely housed origins.

Tritrichomonas foetus is a protozoan parasite that has been recently identified as a causative agent of chronic diarrhea in domestic cats. Transmission of infection occurs by the fecal-oral route through direct contact among animals. Consequently, feline trichomonosis (FT) is more likely to be present in multi-cat environments. The objective of this work was to study the presence of T. foetus and some associated risk factors in cats from densely housed origins and with a reported history of chronic diarrhea. Animals enrolled in this study were family cats (n=15) acquired from pet shops, shelters or breeding centers and cattery cats belonging to one breeding center (n=28) and two cat shelters (A and B, n=25 each). In the catteries, a follow-up analysis for a period of up to 2 months was also performed to determine the parasite shedding pattern in feces and the incidence of infection. Fecal samples were analyzed using in vitro culture and a PCR technique. T. foetus was detected in a total of 38.7% (36/93) of the cats with chronic diarrhea. Parasite infection was similarly detected in family cats and cattery animals (40% versus 38.4%). In the catteries, the parasite was detected in 50%, 44% and 20% of the animals from the breeding center and shelters A and B, respectively. The follow-up analysis showed that 58.3% of infected cats intermittently shed trophozoites in their feces, with an incidence of 23.1%. Investigation of potential risk factors showed that cats ≤1 year old were more likely to be infected than older cats (57.1% versus 27.3%; P<0.05). No significant differences were found when sex and breed factors were studied. These results confirm the importance of FT as a cause of chronic diarrhea in cats and highlight the relevance of close contact conditions for T. foetus transmission.