Despite the fact that some Greyhound adoption agencies (not ours!) recommended the use of Pro-Heart 6 for Greyhounds, the manufacturer has pulled the product from the market.
Pro-Heart 6 is a twice yearly, injectable heartworm medication. During its time on the market, it was responsible for thousands of animals' suffering adverse reactions, and over 500 documented deaths of dogs were also reported to the Federal Food and Drug Administration. Clearly, as it is currently formulated, this is not a product suitable for Greyhounds, or any other breed of dog.
Pro-Heart 6 is manufactured by Fort Dodge Animal Health of Kansas.