Which of the following animal species is most commonly affected by avian influenza?

Chickens are the species most commonly affected by avian influenza. This viral infection primarily targets birds and has a significant impact on poultry populations, especially chickens and turkeys. Chickens can become infected through contact with contaminated environments, infected birds, or their droppings, making them highly susceptible to the disease.

The impact of avian influenza in chickens can range from mild symptoms to severe illness and high mortality rates, particularly in certain strains of the virus. As a result, outbreaks in poultry farms are closely monitored and can lead to control measures, such as culling infected flocks, to prevent the spread of the virus.

While other species, such as pigs and various wild birds, can also be affected by influenza viruses, they are not the primary hosts for avian influenza. Cattle and sheep are not typically associated with avian influenza, further emphasizing why chickens are the most commonly affected species by this specific virus.