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Reasons why your dog licks compulsively

Reasons why your dog licks compulsively


What causes compulsive licking in dogs? Our dog licks almost constantly unless we stop him or he is resting. Sometimes, the licking causes him to vomit several times a day. It is usually a clear liquid, which sometimes contains sand or grass if he has been outdoors.


There are several possible reasons why your dog licks compulsively. Most often, this behaviour is a form of obsessive-compulsive disorder (OCD). OCD is repetitive behaviour that reduces anxiety or stress in the person or animal doing it. There are several behaviour modification drugs that can be used to correct OCD.

With your dog, however, there may well be another underlying reason. Since your dog vomits several times a day and the vomitus consists of a clear liquid +/- sand or grass, the cause of the licking may have a medical basis.

Excessive licking, as well as swallowing and lip-smacking, can in some cases be associated with nausea. The nausea is often caused by a chronic inflammation of the stomach, also known as gastritis. When dogs eat substances that have no nutritional value (such as grass or sand), the behaviour is referred to as pica. Pica can usually be traced back to a behavioural or medical reason. With the history of daily vomiting, a chronic gastritis is strongly suspected. In fact, swallowing sand or grass may well be a form of zoocognopharmacy i.e. a form of self-medicating, in this case for the purpose of trying to counteract excessive acid production in the stomach.

To rule out the possibility of an upset stomach caused by diet or food allergies, talk to your veterinarian. He or she may want to put your dog on a hypoallergenic diet for a few weeks (i.e. a diet that contains only novel ingredients that your dog has never eaten). If the excessive licking and vomiting stops, then you have your answer: the cause is intolerance to an ingredient in the diet or a food allergy.           

If a diet change does not help, then the possibility of a nutritional deficiency may also need to be investigated by your veterinarian since a mineral deficiency (such as sodium or iron) can cause pica in dogs.