North American Veterinary Licensing Examination (NAVLE) Practice Test

Which protozoan organism's presence may suggest a diagnosis of diarrhea in young cats?

1. Giardia intestinalis

2. Tritrichomonas foetus

3. Cryptosporidium

4. Enterobius vermicularis

The correct answer is: Tritrichomonas foetus

The presence of Tritrichomonas foetus in young cats is particularly significant for diagnosing diarrhea, as this protozoan parasite is known to cause gastrointestinal issues in felines. Tritrichomonas foetus primarily affects younger cats, particularly those in shelters or group settings, leading to chronic diarrhea that may be persistent and difficult to treat. Unlike other protozoans, Tritrichomonas foetus often results in inflammation of the intestinal lining, contributing to the hallmark symptoms of diarrhea. The life cycle and pathogenic mechanisms of this organism explain its role in this specific presentation. Young cats, due to their immature immune systems, are more susceptible to infections like those caused by this protozoan. Other organisms listed, such as Giardia intestinalis and Cryptosporidium, are also associated with diarrhea but are less specifically tied to young cats compared to Tritrichomonas foetus. Giardia is more commonly noted in a broader range of species alongside potential signs of illness, while Cryptosporidium can affect young animals but does not typically have the same prevalence or specific impact as Tritrichomonas in this scenario. Enterobius vermicularis, on the other hand, is a pinworm primarily associated with humans and is not relevant in the context of feline diarrhea