Dogs and Cats Pain,h how to recognize pain in your pet. Some signs are more obvious, such as limping or yelping, while others are more subtle, such as excessive grooming or a change in litter box habits. September is Animal Pain Awareness Month, which is a good time to get to know the signs that your pet may be suffering. Be on the lookout for the following behaviors and call your veterinarian if you think your pet is in pain. Never try to treat your pet with human medications since many of them are toxic to animals.