Signs a dog may be in pain include whining or barking, difficulty moving and rapid, shallow breathing, according to Preventive Vet. The dog's heart rate may increase, and the dog may show noticeable personality changes or become incontinent.
Dogs tend to try to hide their symptoms, so subtle behavioral changes can be early warning signs of pain, explains Karen B. London for The Bark. Aggression or grouchiness are common symptoms. The dog may suddenly stop playing with other dogs and growl when they approach. It may be uncomfortable around people, especially if the person tries to touch particular parts of its body. Even friendly dogs may growl or snap to try to protect themselves from further pain. This may become aggravated after exercise.
Dogs may also become withdrawn and lethargic due to pain, notes VCA Animal Hospitals. The dog may lose interest in food and prefer to lay still rather than move. It may move more slowly than normal and try to avoid climbing stairs or jumping on furniture. Dogs also sometimes lick the painful area. In some cases, there may be a noticeable limp or a stiff gait. There are also times when people should assume the dog is in pain even if there are no obvious symptoms. For example, dogs that have recently undergone surgery typically need pain medication as a matter of course.