What is a common sign of infection in animals?

Fever is a common sign of infection in animals because it reflects the body’s immune response to pathogens, such as bacteria or viruses. When an animal is infected, its immune system activates and produces pyrogens, which trigger an increase in body temperature as a way to help fight the infection. This elevated temperature can enhance the effectiveness of the immune response and inhibit the growth of some pathogens that prefer a stable, normal body temperature.

While increased appetite and weight loss can be associated with various health conditions, they are not specific indicators of infection. Excessive grooming may occur as a response to stress, discomfort, or skin irritations, but it does not directly correlate with infection. Thus, fever stands out as a more direct and recognizable sign indicating the presence of an infection in animals.