I’m not bringing up the oddities of our climate to gain sympathy but to demonstrate why most veterinarians now recommend year-round heartworm prevention. Snow in May can lull owners into thinking that heartworms should be the least of their concerns (the disease is transmitted by mosquitoes, after all), but all the precipitation we’ve been getting lately and the warm temperatures that are forecast are the ideal conditions for mosquito populations to flourish.
I’ve written many times about heartworm disease. I thought I’d try a different approach today to appeal to you visual-spatial thinkers out there. The American Heartworm Society (AHS) has produced an excellent infographic that reviews the basics of heartworm disease.
For the most part, I agree with AHS’s assertion that dogs benefit from year round heartworm prevention. In many parts of the country, heartworm disease is transmitted all year long. Even if you don’t live in one of these areas, determining exactly when to safely start and stop giving preventive medications can be difficult, as the weather we’re experiencing here in Colorado shows. Traveling with pets complicates the situation even more, and most of these medications prevent diseases caused by other parasites as well. So, for most busy and slightly distracted owners (I put myself in that category), I do think the safest option is to give heartworm prevention every month, all year long.
That said, medical recommendations should never be one-size-fits-all. If you do live in a cold and dry part of the country with a defined and relatively short heartworm season AND you are exceptionally “on the ball,” taking a few months off in the winter (so long as your pets aren’t travelling) is not all that risky.
It is important to remember that heartworm preventives don’t actually prevent infection; they prevent the progression of disease by killing immature worms that have infected a dog or cat within the last month or so. Make sure not to focus on a recent cold snap while forgetting about the balmy temperatures that preceded it. Despite today’s snow, I’ll be giving my dog Apollo his heartworm prevention this month to cover those 82 degree days that now seem like a distant memory.
Talk to a local veterinarian to determine the best heartworm prevention strategy for your pet.
Dr. Jennifer Coates