Viagra (Sildenafil) is used for more than what it's most famous for. In both humans and canines, the drug is prescribed for severe pulmonary hypertension -- high blood pressure in the lungs.

The disease is physically debilitating, and many affected dogs are unable to walk across the room without collapsing. Once they receive the proper dose of Viagra, these dogs can take short, daily walks with their owners and return to a more normal quality of life.

So if you overhear Viagra being dispensed at your veterinarian's, you'll know its more likely for a heart condition than for "performance." That's especially true, of course, in a neutered dog.

And no, dogs aren't prescribed it for that "other" use.

Biting, destructiveness, noisiness, house-soiling -- these problems can be more of a threat to a pet than a disease such as cancer. That's because too often behavior problems are eventually "solved" by getting rid of the pet, a solution that's often a dead end for the animal.

Even when people refuse to give up on their pets, behavior problems can mean a lifetime of misery. "Bad" pets may spend their lives locked up, locked out or punished in ways that reflect the frustration and ignorance of their owners but do nothing to solve the problems. It's safe to say that neither side realizes the full benefits of the human-animal bond in such sad situations.

It doesn't have to be that way. While some behavior problems aren't fixable, most can be. To accomplish such change, though, you have to be prepared to put some time into changing the situation. Quick-fix, half-hearted efforts are doomed from the start.

The first rule of solving any behavioral problem is to make sure it's not a medical problem. The cat who won't use the litter box may be struggling with an infection that makes urination painful. A dog who snaps when his ears are touched may be suffering from chronic infections. Situations such as these need to be accurately diagnosed and completely treated with the help of your veterinarian before any retraining begins.

When your pet is healthy, your veterinarian can still be of use. While few veterinarians have the training or knowledge to help solve behavior problems, the numbers of those who do are growing -- and your vet may be one of them. Even those veterinarians who have no interest in behavior work can refer you to someone who can help. Loosely grouped under the term "behaviorist," these pet professionals can help fix what ails the relationship you have with your pet.

Consulting a behaviorist can save you time, money and aggravation. Time, because someone with experience in animal behavior can quickly determine the root of the problem, without the emotional baggage that a pet owner may bring to the situation. Money, because a consultation or two is a great deal cheaper than a new sofa. And aggravation? You understand that one if you're living with a problem pet.

Be aware, however, that animal behavior is an unregulated field -- anyone can call himself a behaviorist.

One of the best choices is a veterinarian who's board-certified by the American College of Veterinary Behaviorists. These professionals have gone through years of study in animal health and behavior and have done a residency in the field as well. A plus with this group: They have access to medications being used now to help correct behavior problems.

People with other academic degrees (such as psychology) and people who've picked up their knowledge in the field also make themselves available for advising on behavior. Some can be excellent, so don't let the lack of a DVM or any degrees at all deter you from getting help from someone who has studied in the "school of hard knocks" (or would that be the "school of bites and scratches"?).

Behaviorists are not "trainers" in the sense of offering group obedience classes to sharpen a pet's manners. Instead, they work one-on-one with you to solve a specific behavior problem. The form the consulting takes varies. Some behaviorists consult by phone; others take appointments with or without your pet, while still others make house calls. All these can work, depending on the problem and the pet.

If you're in a situation where your pet is causing problems in your home -- and certainly if you're thinking of getting rid of your pet -- don't delay: Ask your veterinarian for help, or call your closest college of veterinary medicine.