Heartworm: One Bite, One Infection, That’s Enough

Pet owners share some common misperceptions about the importance of monthly heartworm medications. So here’s a public service announcement that could save your pet’s life.

Heartworm infections have been diagnosed in all 50 states of the United States. Dog-to-dog transmission has been documented in 49 (good job, Alaska). Heartworms are presumed to be rampant in wild canids (such as wolves), which act as a holding tank for the infection.

Every single dog that ever goes outside is at risk for receiving a bite from a mosquito and subsequently is at risk for contracting heartworm disease. This includes tiny little Chihuahuas that never leave their owner’s arms and dogs that just go to the dog park once in a while. One bite, one infection, that’s enough.

Mosquitoes do not generally do their mosquito thing when temperatures reach below 50 degrees F. That being said, with erratic and warming temperatures, we are seeing temperatures often climbing above this threshold even in the late fall months and early spring.

Some clients suggest that they stop medicating their pet in September and begin again in March or April. This is a not an effective strategy. There are often warmer temperatures late in the year, and the mosquitoes do not care what month it is.

Heartworm protection is easy to give and relatively cheap. There are many different brands from which to choose and different rebates offered for bulk buying. If one buys a year’s worth, it generally comes out to about $10 a month. The cost of treating heartworms is substantial (especially with bigger dogs). It would surpass the cost of heartworm preventative for your dog’s whole life. Treatment for heartworm also is long, can be painful, and in some cases can be fatal.

Though some breeds, including collies, are known to have reactions to heartworm medication, the medication is generally safe and without complications for most dogs.

There are some homeopathic, more natural insecticides that can help fend off mosquitoes, but there is not one specifically designed to prevent heartworms. Your dog is at risk without heartworm medication.

So what should you do?

The safest thing to do is to make sure that your dog is on heartworm preventative all year long. If you live in a state, such as California, that doesn’t see heartworm disease very often, but you travel with your dog to environments with the disease, your dog is at risk and should be tested. In fact, every dog should be tested once a year to confirm that heartworm disease is not present.

Also, just a quick note that heartworm can be transmitted to cats (though this is rare) and humans (though this is even rarer). Mostly canids, wild and domestic, are at risk.

If your dog is not current on a heartworm test, or if you need heartworm preventative, or if you have any questions or concerns, let us know.

Brett Grossman, DVM
Medical District Veterinary Clinic