Canine Heartworm FAQ

  • Heartworm disease is spread by mosquitoes. 


  • We recommend giving your dog prevention every month all year round because:
    • Michigan weather is crazy. Seriously, we’ve seen mosquitoes in January! It’s not common, but it happens.
    • Heartworm prevention works backwards – it kills any “baby heartworms” acquired from mosquitoes in the last month before they can turn into adults. Even if it’s freezing by January, if December was unseasonably warm, you need to give prevention in January to make sure your dog is safe.
    • Heartworm preventions also deworm against other intestinal parasites like roundworms, hookworms, and with Sentinel Spectrum, whipworms and tapeworms. Some of these parasites can live in the soil for up to 7 years and can even be acquired in freezing weather.
    • It’s easier to remember if you stay with the same routine all year. Pick a day of the month to be heartworm prevention day and stick with it! A lot of people pick the 1st, but any day works. What’s your lucky number?
  • “I’ve never given prevention before or I haven’t given it regularly and my dog tested negative. Why should I start giving prevention?” It’s luck of the draw. Here at KAH, we generally get 5-10 positives per year. Those dogs have to undergo an expensive (exceeding $1000 in some cases!), painful treatment with an arsenic-based medication. While they’re in treatment, they have to be kept on strict cage rest for 2-3 months. In severely affected dogs, heartworm disease or even treatment can prove fatal. Simply put, it’s not worth the risk. You can buy 5-10 years’ worth of monthly prevention for the same cost as treatment, and spare your dog the discomfort and risk of treatment. Prevention is easy and very effective.

For more information about heartworm disease in both dogs and cats, check out the American Heartworm Society