Heartworms are a fatal parasitic condition for animals. In a 2004 study by the American Heartworm Society, Georgia was found to have the third-highest reported incidence of heartworm in the United States, surpassed only by Florida and Texas. But you can protect your pet.

Here's what you need to know:

• Outdoor dogs aren't the only target: Vets estimate that 10 percent to 20 percent of cats also contract heartworms if they aren't on a monthly preventative. Indoor pets contract them almost as often as pets that spend the majority of their time outdoors.

• Mosquitos are the real culprits: Mosquitoes that bite an infected dog, pass on the larvae when they bite other animals. Within six months of infection, the larvae mature into 11- to 14-inch worms that move into the arteries of the lungs as well as the right side of the animal's heart. The worms can live five to seven years in dogs, two to three years in cats.

• Treating animals for heartworm can be dangerous and expensive: Worms die off during treatment. During this time, they can enter the lungs and cause severe damage. Dogs must be kept very quiet for several months during the treatment, which can range from $400 to more than $1,000 based on the severity and treatment plan.

• Dogs primarily get treatment: Because of the high fatality risk, cats aren't normally treated for heartworms.

• Prevention is easy and inexpensive: Vetrinarians sell monthly preventatives that range in price, from $50 to $70 a year for dogs and cats, depending on the animal's weight. Pet owners also can surf the Internet for lower prices on prescription refills.

• Preventatives must be given monthly: Mark the date on your calendar.

• Bug spray won't help: Never apply insecticides meant for humans, especially those containing DEET, on pets. Also, some repellants used for dogs can kill cats so read and follow label directions closely.

For more information on heartworms visit: heartwormsociety.org