MANHATTAN -- Pets need food and water, love and attention. But they also need a quick dose of preventive medicine to keep them healthy.

Heartworm disease is a potential killer in dogs, ferrets and cats, said Dr. Kathy Gaughan, an assistant professor in the College of Veterinary Medicine at Kansas State University. Prevention is available as a tablet or chewable treat that owners can administer to their pets only once a month. Daily and six-month dosages are also on the market, but the once-a-month treatment year-round is the one Gaughan recommends.

The preventive medicine runs about $5 to $10 per month, depending on the size of the animal, and is better than the alternative: an animal who gets the disease will have to face two or three intramuscular injections of an arsenical drug.

Pets get heartworms from the bite of an infected mosquito. The mosquito acquires the disease when it bites an infected animal, usually a dog, which has immature heartworms circulating in the blood. In animals, heartworms cause inflammation of the vessels in the lung, leading to pulmonary hypertension. As a result, heart disease and heart failure can occur.

Symptoms of heartworm may include coughing, difficulty breathing, excessive panting, exercise intolerance and lethargy. A simple blood test can confirm the disease, Gaughan said.

Recovery and future health problems of animals that contract heartworm disease depend on the severity of the disease, which depends on the number of heartworms present, and the presence of other unrelated diseases, she said.

"Dogs with low worm burden are more likely to make full recovery than dogs with high worm burden," Gaughan said.

In Kansas, pets are less likely to get heartworm than animals in the southeastern United States, but are more likely to contract the disease than pets in the northwestern part of the country. Dogs are about 10 times more likely than cats to be infected with heartworms, although the disease is harder to detect in cats.

"Sudden death can occur without prior symptoms in cats," Gaughan said.

This is why they strongly recommend preventive heartworm medicine for dogs. For cats, the medication is recommended for those that spend significant time outdoors. The preventive medicine has been tested vigorously for its safety.

"Prevention of heartworms is easier and less risky than treatment," Gaughan said. "Prevention is less costly as well."