North American Veterinary Licensing Examination (NAVLE) Practice Test

The presence of caseous accumulations in the throat of chickens is highly indicative of trichomonosis. This disease, caused by the protozoan parasite Trichomonas gallinae, often manifests as lesions in the oral cavity, esophagus, and crop of birds. These lesions can appear as yellowish, cheesy masses, which can lead to difficulty in feeding and drinking, contributing to the overall clinical signs observed in the flock.

Caseous masses are a hallmark of this disease, differentiating it from other conditions. For example, candidiasis typically presents with a more yeast-like infection, affecting the gastrointestinal tract but not producing caseous lesions in the throat. Infectious coryza is a bacterial upper respiratory disease that primarily results in nasal discharge and conjunctivitis rather than visible caseous accumulations. Aspergillosis, caused by fungal infection, usually leads to respiratory issues and granulomatous lesions but does not typically present as caseous throat lesions either.

Given the specific symptom of caseous deposits in the throat, trichomonosis clearly emerges as the most likely diagnosis in this scenario.