Which of the following are considered signs that an animal is ill?

Loss of appetite and breathing difficulties are significant signs that an animal may be ill. When an animal exhibits a lack of interest in food, it can indicate various health issues ranging from minor gastrointestinal disturbances to more serious conditions requiring medical attention. Breathing difficulties are also a major concern, as they can indicate respiratory distress, heart problems, or other critical health issues. These signs typically suggest that the animal's body is not functioning properly, and they necessitate a closer examination by a veterinarian to determine the underlying cause and appropriate treatment.

In contrast, the other options represent behaviors and conditions that suggest an animal’s health is normal or stable. Playfulness and a good appetite often indicate that an animal is healthy and engages in usual behavior. Similarly, bright eyes and a shiny coat are external indicators of good health, and being active and alert are signs that the animal is feeling well and does not display any signs of distress or illness. Recognizing the differences in these behaviors is essential for assessing an animal's health status effectively.