In 2012 alone, an estimated 2.8 million dog owners give their dogs antidepressants.
With a growing number of pets being left alone all day while their busy owners are out working, veterinary surgeons have reported that more and more of them are suffering from 'separation anxiety'.
They fear it has become common for some to give their animals tranquilizing and antidepressant drugs to treat symptoms such as bad behavior and aggression.
The trend has prompted vets to warn that such use of drugs is masking the real problem and makes a mockery of Britain's claim to be a nation of animal lovers.
Andrew Knight, professor of animal welfare and Ethics at the University of Winchester, said: "The number of behavioral problems in dogs and cats, and even other pets, such as birds), seen by veterinarians is huge.
"We're constantly seeing animals that are aggressive, unduly fearful, or barely under control when they visit, although my colleagues and I do our best to put them at ease with gentle handling and tasty treats."
Dr. Knight, a member of the Royal College of Veterinary Surgeons, said most of the problems seen by his colleagues were due to "poor socialization and training" when the animals are young, compounded by a lack of understanding of their needs as adults.