STEVE DALE: Protect your pooch from heartworm. No excuses!

Around 60 percent of dogs are protected against mosquito-transmitted heartworm disease. And while that figure may sound acceptable to some, it certainly does not to Dr. Thomas Nelson, president of the American Heartworm Society.

"That means 40 percent -- approaching half -- are not protected," says Nelson. Since heartworm disease is potentially deadly and absolutely avoidable when a dog is given a monthly preventative, he adds, "We have to do better."

Nelson admits some owners are concerned about giving their dogs medication of any kind. Heartworm preventative is "a very safe class of drug," he says. "We really don't see adverse reactions."

Could it be veterinarians are not emphasizing the importance of prevention? "Perhaps, but mostly I don't believe that is true," says Nelson. "However, it is true that some people don't routinely visit the veterinarian. And veterinarians can't communicate to clients unless they have the opportunity."

Some dogs do survive heartworm disease without showing symptoms, even with up to several dozen spaghetti-sized worms living in their lungs. "True enough," concedes Nelson, who adds that some people continue to smoke cigarettes because they know other smokers who've never developed lung cancer.

Mention price as an "excuse" for not buying a heartworm preventive and Nelson becomes vehement. "No, I don't buy it," he says. "It's an excuse, and not a very good one. If your pet isn't worth 10 to 25 cents a day, something isn't right."

What's more, all monthly heartworm preventives also protect against other internal parasites such as hookworm and roundworm; and some heartworm meds protect against external parasites, likes fleas and ticks.

"I'd argue all that protection in one place is a bargain," adds Nelson, a veterinarian in private practice in Anniston, Ala.

Roundworm, in particular, is a potentially serious problem, which Nelson says isn't spoken about often enough. Nelson, a member of the Board of Directors of the Companion Animal Parasite Council, explains that not only can roundworm be transmitted from dogs to humans, it can also cause blindness in people. This doesn't occur often, but when it does, it strikes mostly children.

"Instead of worrying about worming dogs, we're now advocating prevention in the first place," Nelson says.

Nelson will be among the experts participating in the American Heartworm Society 2007 Triennial Heartworm Symposium in July in conjunction with the American Veterinary Medical Association Annual Convention in Washington. Researchers from around the world will speak at the symposium, revealing the newest and latest breakthroughs.

While expensive to treat, heartworm disease, once diagnosed, is treatable. However, that treatment is arsenic. No surprise, this is one of those cases that while treatment is necessary, it can be nearly as problematic as the disease.

Only a few years ago, researchers learned that a bacterium called wolbachia is always present with heartworm, and, in fact, likely necessary for the heartworm to exist. John McCall, professor emeritus at the University of Georgia College of Veterinary Medicine, Athens, combined Ivermectin (used to prevent heartworm) with an antibiotic (to deal with the bacterial wolbachia) and documented a nearly an 80 percent kill rate. When some of the traditional arsenical medication is added into the mix, the kill rate approaches 100 percent. What's more, there's little damage to the lungs, which is a part of the adverse impact of arsenical medication when used alone.

"We're nowhere ready to recommend this treatment yet, but this is very promising for the treatment of heartworm disease," says McCall. To learn more about heartworm disease and other internal and external parasites that can effect people and pets, check out these Web sites:

Companion Animal Parasite Control:

American Heartworm Society: