What sound indicates pain or distress in animals?

Yelping is a distinct vocalization often associated with acute pain or distress in animals. It is a sharp, high-pitched sound that typically indicates that an animal is experiencing discomfort, fear, or an urgent need for help. This behavior serves as a communication method, alerting both other animals and humans to the fact that something is wrong.

In contrast, while howling might be associated with distress in certain contexts, such as a dog finding itself alone or signaling its location, it is also a natural form of communication among canines. Crying can indicate various emotions, including distress, but it can also be used by animals in non-painful situations. Purring is usually a sound of contentment in cats, although it can occasionally be associated with discomfort, but it generally does not signal acute pain. Therefore, yelping is the most specific sound to indicate pain or distress among the options provided.