On July 2, 2019, the FDA-CVM announced approval of ProHeart 12 (moxidectin), a 12-month extended-release injection for dogs age 12 months or older for the prevention of heartworm disease. ProHeart 12 is also approved for the treatment of existing larval and adult hookworm infections.

Moxidectin is a macrocyclic lactone antiparasitic compound already approved in an extended release formulation as ProHeart 6, with a six-month duration of action for heartworm disease prevention. The ProHeart 12 formulation is the same as the previously approved product but contains three times the concentration of moxidectin, resulting in a 12-month duration of action.

Heartworm disease is serious and can result in severe lung disease, heart failure, other organ damage, and death in pets—mainly dogs, cats, and ferrets. Heartworm disease is caused by a parasitic roundworm called Dirofilaria immitis. The worms are spread through the bite of a mosquito. While living inside a dog, the worms mature into adults, mate, and produce offspring.

The worms are called “heartworms” because the adults live in the heart, lungs, and associated blood vessels of an infected animal.  In the United States, heartworm disease has historically been most common along the Atlantic and Gulf coasts from the Gulf of Mexico to New Jersey and along the Mississippi River and its major tributaries, but it has been reported in dogs in all 50 states.

Treatment for heartworm disease can be potentially toxic to the dog’s body and can cause serious complications, such as life-threatening blood clots to the dog’s lungs.  Treatment is expensive to the pet owner because it requires multiple visits to the veterinarian, blood work, x-rays, hospitalization, and a series of injections.

The effectiveness of ProHeart 12 was demonstrated in two laboratory dose confirmation studies and a field study of 297 client-owned dogs that were administered the product. All studies demonstrated the product to be 100 percent effective in the prevention of heartworm disease for one year.

ProHeart 12 is available in two sizes – a 10 mL size and 50 mL size – and is manufactured by Zoetis Inc., based in Kalamazoo, Michigan.

Click here to read information about safety evaluation of ProHeart12.

Click here to read important facts about heartworm disease.