If your dog is barking mad, help is at hand. You can give it some Prozac.

A dog version of the anti-depressant drug has been launched in America and will soon be available in Britain.

It will be used to treat a canine compulsive disorder in which faulty genes combine with stress to produce excessive licking, whimpering and tail-chasing.

The drug, called Reconcile, comes in a beef-flavoured chewy form and is also expected to curb compulsive pacing, chewing and dribbling.

Prozac, which has been used to cure compulsive behaviour in humans, works by increasing the brain’s levels of serotonin, a mood-lifting chemical.

Trials involving more than 660 mentally disturbed pets in Europe and America produced improvements in behaviour within eight weeks.

“Treatment for companion animals is a relatively new area for us,” said Eli Lilly, the drug’s US manufacturer, which has been granted a licence by Britain’s Veterinary Medicines Directorate.

Animal behaviour research shows that as many as 8% of dogs suffer from canine compulsive disorder. But critics say dogs are now being diagnosed with “lifestyle” illnesses so that drugs can be marketed to treat them.

Roger Mugford, an animal psychologist, said: “Most breakthroughs in [dog] behaviour are achieved by carrying a titbit and using it wisely, not by drugs