What is the most likely diagnosis for a hawk showing difficult breathing, weight loss, and trouble eating?

The most likely diagnosis for a hawk exhibiting symptoms such as difficult breathing, weight loss, and trouble eating is aspergillosis. This fungal infection, caused by the Aspergillus species, primarily affects the respiratory system, leading to respiratory distress. The difficulty in breathing can arise from the inflammation and damage to the air sacs and lungs that the fungus causes. As the condition progresses, affected birds may also exhibit weight loss due to reduced appetite and energy expenditure associated with trying to breathe.

Weight loss is particularly significant here, as stress from respiratory illness often leads to a diminished desire to eat. The combination of respiratory distress and weight loss makes aspergillosis a strong candidate considering these symptoms. In addition, hawks can be exposed to the Aspergillus fungus in their environment, which increases the prevalence of this condition.

Other conditions, while potentially serious, might present with different or additional symptoms that do not align as closely with the combination of issues observed in this case. For example, apoplexy typically involves sudden death or neurological symptoms rather than respiratory issues. Coccidiosis primarily affects the intestinal tract and would usually manifest as gastrointestinal distress rather than respiratory difficulties. Frounce, caused by a protozoan parasite, typically presents with mouth