3 Tips for Preventing the Spread of Canine Heartworm Infection During Transport

Heartworm disease is a serious health problem and, according to The American Heartworm Society, continues to expand across the United States due to an increase in mosquito populations, shifting wildlife territories, and changes in weather patterns. Animal relocation programs can do many things to prevent the spread of heartworms, including treating known heartworm positive dogs before moving them to a different region of the country. It’s best to wait at least 30 days post-treatment before transporting dogs who have been treated for heartworm.

If you must move an infected dog, be sure to check with the destination state veterinarian’s office to be sure it’s legal to import heartworm positive dogs. Then, follow these three tips to ensure transported dogs are part of the solution and not part of the problem:

1. Check for circulating microfilariae. Microfilariae are “baby” heartworms that are transferred to a mosquito when it feeds on an infected dog. When the mosquito feeds on another dog, the microfilariae can then be transferred to the new dog. Check a blood sample under a microscope for circulating microfilariae. Eliminate the microfilariae by following tips two and three below so dogs can’t contribute to the spread.
2. Use heartworm preventive year-round. Preventives containing topical moxidectin (i.e., Advantage Multi® or Coraxis®) are very effective at quickly reducing the infective microfilarial stage. They also start to weaken the adult heartworms that are producing the microfilariae.
3. Prevent new microfilariae from developing by using doxycycline. This antibiotic will help keep any new microfilariae from developing and will prohibit any existing microfilariae from being passed on to a mosquito.

When a heartworm positive dog arrives at the new location, treatment for heartworm disease can begin as soon as the dog is settled in the new location.

For more information about heartworm transmission, read Minimizing Heartworm Transmission in Relocated Dogs and Heartworm Disease Management in Animal Shelters.