ProHeart 6, a heartworm drug manufactured by Fort Dodge Animal Health, will be reintroduced to the U.S. market after previously being withdrawn because of serious life-threatening adverse reactions, including loss of appetite, lethardy, vomiting, seizures, difficulty walking, jaundice and bleeding disorders, allergies, convulsons followed in some cases by death.

The announcement, made on Thursday, follows a review of scientific data by the Food and Drug Administration’s Center for Veterinary Medicine, which supported the returning of the product to the U.S. market on a restricted basis.

Rami Cobb, Fort Dodge’s senior vice president of pharmaceutical research and developmental said in a release that the drug protected millions of dogs worldwide against potentially deadly heartworm disease. Heartworm disease is cause by a parasite that is transmitted through the bite of a mosquito.

Any veterinarian or dog owner who wants to purchase the drug will first have to register with Food Dodge Animal Health as well as to enroll in an Internet training program prior to obtaining the product.

“This is the first veterinary drug to be marketed under a risk minimization and restricted distribution program. While we concur with the limited return of ProHeart 6 to the US market we strongly encourage veterinarians and pet owners to report any possible adverse reactions,” Bernadette Dunham, D.V.M., Ph.D., director of FDA’s Centers for Veterinary Medicine said.