Some families living in the northern half of the U.S. choose to drop heartworm protection for their dogs for a month or two during winter. The feeling is that mosquitoes aren’t around in high numbers to spread the disease, so why not save money on that extra dose or two?
Unfortunately, that thinking may lead to a lot more expense for owners and danger for pets, making year-round protection important. Mild winters, such as the current one for the northern half of the country, mean that mosquitoes may actually hatch out and be feeding even in January. Many northern areas have big “thaws” midway through winter every year with temperatures rising high enough to accommodate mosquito life cycles.
Heartworm medications work retroactively, so the dose you give today actually covers your dog for last month. Can you count on accurately remembering if you had any warm days last month? Most people can’t.
If you are a “snowbird” who leaves the cold and snow behind to winter in the South, your dog will definitely need heartworm protection. That protection needs to continue once you return up North – even if it is blizzarding outside. Remember the retroactive action!
In addition, many heartworm pet medications protect your dog from more than just heartworm disease. Depending on the medication, your dog may be protected from internal parasites and even external parasites in some cases. The Companion Animal Parasite Council suggests you discuss parasite prevention with your veterinarian and, in almost all cases, recommends year-round protection.
As the map shows, heartworms are present over most of the US. Even if your home area does not seem to be represented, odds are that you travel to a danger zone or come in contact with other dogs that have traveled to a danger zone. These dogs can bring heartworm into your area which can pass along infection to your dog. One bite from an infected mosquito may be all it takes to cause heartworm disease. Treatment is expensive and dangerous, making heartworm prevention the best option for most pets. In addition, your dog may end up with some permanent damage from the infection – even if caught early.