Guard your pets most precious organ from invasion.

Its hard to fathom how worms can live inside your puppys beating heart, but they can, and if your pet gets infected they could severely damage her heart and lungs.

Heartworms spread by traveling inside mosquitoes as larvae, or immature worms. When infected mosquitoes bite your puppy, the heartworm larvae transfer to your pet and work their way to her heart. Once there, the worms grow, feeding off the lining of the heart and plugging essential blood vessels.

Because mosquitoes spread them, heartworms are found throughout the world. In the United States, the incidence is highest along the southern Atlantic and Gulf coasts. The disease is less common along the northern borders and at higher elevations.

Prevention
If mosquitoes are biting you, chances are theyre biting your pet too, so you need to protect her from heartworm disease. Happily, new preventive medications cause few side effects, combine heartworm prevention with other parasite control, and come in convenient once-a-month doses.

If your puppy is more than 6 or 8 weeks old and less than 6 months old, depending on the product your veterinarian recommends, she can begin taking the medication immediately without undergoing any blood tests.

Dogs older than 6 months who are not taking preventive medication may already be infected with reproducing adult heartworms. If your puppys in that group, your veterinarian needs to use a blood test to confirm that your pet is heartworm-free before she can start taking the medication.

Why? If an infected dog takes heartworm preventives she runs the risk of an anaphylactic-shock reaction, because the treatment involves a sudden killing of microfilaria, or baby heartworms, present in the bloodstream.

Prescription Products
There are several medications on the market:

• Interceptor (milbemycin oxime) comes in a chewable tablet and guards against heartworms, hookworms, roundworms, and whipworms.
• Sentinel combines Interceptor with Program (lufenuron), a flea-control agent.
• Heartgard Plus (ivermectin and pyrantel) comes in a chewable cube and guards against heartworms, hookworms, and roundworms.
• Proheart (moxidectin) comes in tablet form and protects against heartworms.
• Revolution (selamectin) is the latest in heartworm prevention technology. You apply a few drops of the liquid medication to your pets skin to guard against heartworms, fleas, ticks, ear mites, and sarcoptic mange mites.

Any of these prescription medications gives your pet excellent protection against heartworms.

Treatment
If your dog does get heartworms, she can be treated. But the treatment involves expensive injections with potentially toxic reactions, so its best to start prevention early to preserve your pets health and your pocketbook.