Which protozoa is responsible for the disease known as frounce?

Frounce, also known as avian trichomoniasis, is a disease caused by the protozoan parasite Trichomonas gallinae. This parasite primarily affects birds, especially pigeons and doves, and is associated with infections in the upper digestive tract.

Trichomonas gallinae leads to lesions in the oral cavity, esophagus, and crop of affected birds, manifesting as symptoms such as difficulty in swallowing, respiratory distress, and even sudden death in severe cases. Understanding the life cycle and transmission of this parasite is crucial for effective management and prevention of the disease in avian populations.

While Giardia and Histomonas are also protozoan parasites, they are responsible for different diseases, such as giardiasis and histomoniasis, respectively. Ascaris, on the other hand, refers to a type of roundworm and is not a protozoan, further distinguishing it from the other choices listed. This contextual knowledge is important for recognizing the specific role of Trichomonas gallinae in the manifestation of frounce in birds.