Posted Wednesday, July 23, 2008, 4:23 p.m., EDT

A mosquito population explosion caused by recent Midwest flooding is a good reason for pets to be on heartworm medication this summer. Steve Thompson of Purdue University’s School of Veterinary Medicine said mosquitoes are a potential danger to cats, dogs and ferrets because they are susceptible to heartworm infection.

If left untreated, heartworm can be fatal. Given the heavy rainfall throughout states such as Indiana in recent months, mosquito breeding is high, and could lead to more heartworm cases this year.

“The mosquito population burst we’ve had in the past few weeks has made it difficult,” Thompson said. Pets that have not been tested in the past six months for heartworm should have one, he added. 

“The good thing about heartworm prevention is that it literally works 45 days backwards. With any mosquito bite a cat or dog received during the past month, or even longer, the young worm can be killed in the skin before reaching the heart,” he said.

Heartworm preventive medication can be administered orally, by a liquid treatment applied to the back of a pet’s neck, or by a longer-acting injection. In dogs, heartworms more easily complete their whole life cycle and reach the heart, compared to cats, Thompson said.

In cats, heartworm can cause sudden lung problems and asthma-like coughing as larvae migrate through the lungs to the heart. Cats can appear healthy moments before a coughing attack. <HOME>