Exploring heartworm prevention for dogs without vet prescription is a growing concern among pet owners in the United States. Heartworm disease is a serious and potentially fatal condition transmitted by mosquitoes, requiring timely and accurate prevention. Most heartworm preventives are classified as prescription medications because incorrect use can lead to serious health risks, including ineffective protection and adverse reactions. Obtaining heartworm prevention for dogs without a vet prescription bypasses essential veterinary evaluation, such as testing for existing infections. US regulations require a prescription to ensure proper diagnosis and safe, effective use of preventive treatments, protecting the long-term health of dogs.