The AVMA learned that veterinary prescription products, such as heartworm preventive drugs for dogs and cats, were made commercially available through eBay.
The AVMA understands that in some countries, heartworm preventive drugs are sold over-the-counter; however, in the U.S., heartworm products must be sold within a veterinarian-client-patient relationship (VCPR). Prescription drug products, including heartworm preventive drugs, can cause substantial adverse effects in animals, especially when used improperly and outside the order of a veterinarian.
Full AVMA Response:
The AVMA responded on November 5, 2009. (PDF)