BRIAN A DIGANGI, DVM, MS, DABVP
Q. The American heartworm Society (AHS) and the Association of Shelter Veterinarians (ASV) recently released a set of best practices for transporting dogs. Why?
A. The AHS and ASV saw a need for heartworm-specific transport recommendations to guide veterinarians and animal shelters. Heartworm disease has become more widespread in the U.S. over the past several decades, due in part to the increased movement of heartworm-positive dogs to regions where heartworm disease was once uncommon. When mosquitoes feed on a microfilaremic dog, they become heartworm vectors capable of transmitting heartworms to unprotected pets.
Dogs are transported for multiple reasons, including travel with vacationing or emigrating owners, participation in competitions, and relocation for adoption. When natural disasters such as the 2017 hurricanes strike, the number of transported pets rises due to animal displacement. Dogs with no history of veterinary care are at increased risk of being infected, especially if they come from heartworm-endemic areas. The new recommendations will help these animals and those living in the destination region remain healthy.
Q. Not every rescue organization can afford to treat infected pets. What practical steps can be taken to prevent heartworm transmission?
A. In an ideal world, heartworm-positive rescue dogs would be treated at their location of origin before being moved. Unfortunately, the cost, labor and time entailed in heartworm treatment can be a barrier, and circumstances often dictate that infected animals will be unable to complete a full course of heartworm treatment, including adulticide administration, before being moved. The AHS/ASV best practices (summarized below and available in their complete form at heartwormsociety.org and sheltervet.org) can help ensure that heartworm transmission is averted. They include:
- Testing of all dogs 6 months of age or older prior to relocation
- Relocation delay for heartworm-positive dogs
- Pre-treatment (e.g. administration of macrocyclic lactone drugs, topical insecticides and doxycycline) for heartworm-positive dogs when relocation cannot be delayed
- Guidelines for microfilaria testing and retesting to avoid the transport of microfilaremic dogs
- Guidelines for transport following administration of melarsomine to infected dogs.
Q. What should I do if a client adopts a heartworm-positive dog?
A. The compassion that moves owners to adopt these dogs saves many lives, and owners willing to take on the financial responsibility and caretaking commitment involved in adopting and treating heartworm-positive dogs should be commended. Veterinarians should support and encourage these owners, while ensuring they understand how to safeguard the health of their new pets and pets in their communities.