Licking is a form of communication for dogs. It can be a way for dogs to gain acceptance from those who are higher up in rank. Dogs also lick out of curiosity, as a natural way to explore their environment. Younger dogs especially do this. When licking becomes excessive, however, it may be a sign that something deeper is wrong, such as stress or even an underlying medical condition.
Obsessive Compulsive Behavior
Dogs sometimes engage in obsessive compulsive behavior when they are bored, frightened or experiencing conflicting emotions. These behaviors become compulsive when they're done excessively and without provocation from the environment. Frequent licking of self, the air or inanimate objects can be an example of this type of behavior. Other examples include frantic spinning, persistent barking, pacing and tail chasing. Often this behavior results from stress that the dog is experiencing, but sometimes it can be a symptom of an underlying medical condition.
A dog who is confined, tied up or forced to live in a small area for long periods of time may exhibit obsessive compulsive behaviors such as frequent licking. A dog also may act compulsively if he's in a competitive, hostile, unstable or unpredictable environment, experiencing abuse or is isolated and suffering from separation anxiety. These situations cause dogs to respond by acting strangely in an attempt to cope with and adjust to their circumstances. Also, if a dog hasn't been socialized with many people or dogs before he may act erratically.
Excessive licking of themselves or others can sometimes be a symptom of a gastrointestinal disorder. Gastrointestinal diseases can include inflammatory bowel disease, delayed gastric emptying, irritable bowel syndrome, chronic pancreatitis, gastric foreign body or giardia infection and may also include symptoms like nausea. Other medical conditions that can influence your dog's behavior are epilepsy, head injuries or bacterial and viral infections. In these cases, take your pet to a veterinarian to deal with the underlying causes.
Age-Related Cognitive Dysfunction
If your dog is over 6 years old and is beginning to exhibit strange behaviors such as excessive licking, it could be a sign that he is suffering from cognitive dysfunction. Cognitive dysfunction is a condition that can affect older dogs and sometimes causes dogs to lick objects or others a lot. As dogs age, their mental functioning can deteriorate, causing them to act compulsively. Other symptoms of cognitive dysfunction may include disorientation, engaging less frequently in social interaction and forgetting previously learned behaviors. If your dog is middle-aged and you suspect he may be suffering from cognitive dysfunction, consult with your veterinarian.