What is a common symptom of avian influenza in poultry?

Avian influenza, or bird flu, is a viral infection that affects various species of birds, particularly poultry. A prominent symptom of this disease is upper respiratory distress, which can manifest as coughing, sneezing, nasal discharge, and difficulty breathing in affected birds. This respiratory impact occurs because the virus targets the respiratory system, leading to inflammation and impairment of normal respiratory function.

In contrast, the other options do not align with the known symptoms of avian influenza. For instance, increased laying rates, improved feathering, and higher weight gain are not typical indicators of this viral infection in poultry. In fact, avian influenza can often lead to decreased egg production, poor feather condition, and weight loss due to the negative impacts the virus has on the overall health and well-being of the birds. These associations emphasize how important it is to recognize upper respiratory distress as a key symptom of avian influenza in poultry.