Mental illness is not exclusively a human problem, says animal psychologist Michael Fox, 38. A graduate of the Royal Veterinary College in London, he is now an associate professor of psychology at Washington University in St. Louis. In his best-selling Understanding Your Dog and in his nationally syndicated newspaper column, Ask Your Vet, Fox tries to explain why an increasing number of pets are neurotic. Author of another book, Between Animal and Man, to be published in June, he plans to leave Washington University in September to become director of the U.S. Humane Society's Institute for the Study of Animal Problems. In St. Louis, Fox talked about the psychological problems of pets with John McGuire for PEOPLE.

Is there an increase in mental illness among pets?

Absolutely. And this will continue to increase because people want an intimate relationship with their pets. Dependency is an important key to the development of conflict and neurosis. With increasing dependency on its owner, the pet becomes more vulnerable psychologically.

How do you know a dog is neurotic?

One type of neurotic behavior is excessive aggression by the male dog toward the female. Another form has the dog being terrified of another dog. That can come from being raised exclusively among people. The pet literally thinks of itself as a human being. Some dogs like that have problems breeding—they would sooner breed with their owners.

Are there incidences of "sibling rivalry" between pets and children?

Yes. One of the best examples of this I know is a Pekingese that developed a paralysis in both hind legs. It was a purely psychosomatic, hysterical reaction because its owner had her own human baby. This dog had been a child substitute for many years. My research has shown that dogs and cats have the same emotional centers as human beings, so they have the same emotional capacity to feel and express.

What are some other physical symptoms of emotional difficulty?

Hives, asthma, vomiting, severe diarrhea, among others.

When these occur what steps should the pet owner take?

The difficulty could be psychosomatic. It could also have some clinical disease origin, so see a veterinarian. Unfortunately, a lot of veterinarians are like human doctors. They push pills. There are a lot of people calling themselves animal psychologists, but they must have a very good basis in clinical medicine to make an accurate diagnosis. Otherwise, these people are quacks.

Are you worried about the quacks?

I am more concerned about people having pets without knowing how to treat them right, not understanding their problems—and then giving up on them. Irresponsible ownership accounts for 4 million unwanted dogs and cats being destroyed every year. That is a grotesque figure!

What role do pets play for their owners?

Increasingly, they fill the role of an emotional crutch. A lot of people want a dog because they always had one when they were kids. They marry, get a dog, and then the husband and wife both go off and work. They leave the dog alone in the house or the apartment, and this is extremely stressful for the dog. He begins destroying the house, becomes unhousebroken, barks a lot. The animal is getting back at its owners because he is lonely. Instead of punishing the dog, owners should try to understand what it's trying to communicate.

Whenever a pet acts strangely, is it trying to tell its owner something?

Sometimes the pet is emotionally upset, but there may also be a genetic factor. Inbreeding has become a terrific problem. For instance, a Saint Bernard, normally a very docile, sweet and affectionate animal, becomes easily afraid and dangerously defensive when he reaches maturity at 1 or 2 years of age. Suddenly he won't allow the master into the house. If socially maladjusted behavior like that is genetic in origin, then the responsibility is not the owner's, but the breeder's. Once a breed becomes popular, it becomes sort of mass-produced and the quality drops. This is a serious issue today in pet ownership. The breeders should keep careful progeny records, but they are often remiss.

What else causes genetic problems?

When we domesticate an animal, nature no longer has control. So we have to assert the control, to cull out those that are unstable. In the show ring today there is greater emphasis on good looks and good carriage than on good temperament.

Which breeds have been adversely affected by inbreeding?

The cocker spaniel is the classic example. Years ago, when the cocker won a few shows, people thought how nice it would be to own one. A lot of these dogs became hysterics, emotionally unmanageable. They would spend half their lives on tranquilizers. The toy poodle is another dog that can have problems. It is hyperactive, sometimes quite prone to epilepsy. The German shepherd has been known for its unstable temperament for the last 30 or 40 years, but not all German shepherds are like that, of course.

Which breeds do you favor?

The mongrel is the Renaissance man of dogs. It is more flexible and intelligent, like the wolf. Mongrels and wolves use all their abilities. Among the purebreds the golden retriever is the best in temperament and adaptability.

Is an intelligent dog easier to train?

Trainability is more related to dependency than intelligence. Cats are very intelligent but damned hard to train. They're very independent. Siamese are considered most doglike, and consequently they have more emotional problems.

How do you compare emotional breakdowns in dogs with delinquency in teenagers?

The dog, like the teenager, needs a strong, supporting parent-leader. If you are too permissive with a dog, you get a canine delinquent. If you are too dominant and exert excessive control, you end up with a cringing dog. It's the same with a child.

Has increasing urbanization compounded the problem of mental health among animals?

The biggest problem is confinement. All dogs need a certain amount of activity every single day. They enjoy running. But now dogs have to be on a leash in many parks, and sometimes they aren't allowed at all. We are going to have to develop new breeds of dogs that are adaptable to the urban way of life. Either that, or accept the fact that the cat is the pet of the future. Cats adapt extremely well to apartment life.

Do dogs and cats ever reflect their owners' problems?

The emotional problems pets have are usually related to certain tensions in the household. In a sense the pet is like a litmus paper, or a mirror.

Can a person be too attached to a dog?

As long as the relationship isn't detrimental to the people or the dog, it's okay. If the pet is treated like a baby, or if the owner makes it wear clothes when it goes outside, that can be all right, too. A lot of people do that. It's a question of personal values. If the dog is happy being a child substitute, fine. But if he becomes a tyrant in the house, that's a big problem.

Do dogs have sexual problems?

The situation is utterly inhumane. I think it's a kindness to spay them or castrate them, so that they can adapt more easily to the urban way of life.

In essence, how would you describe man's relationship with animals?

A child and a puppy go through the same stages of emotional development. The means of communication are similar, as are the displays of emotion. Man is both animal and God. He's animal in terms of his heritage, his evolution and his kinship with all life. He's God in terms of his responsibilities as a steward.

But don't many people deny man's emotional kinship with other animals?

Yes, a lot of scientists will say that animals don't have emotions like we have. There is a widespread assumption, for example, that the dog has no insight, no intuition, no ability to reason. Generally, I think the dog knows more about its owner than the owner knows about the dog. I think a lot of people ought to let the dog train them.