I have been thinking about this blog post for several months. I hesitated to write it, because I am not a veterinary professional and I don’t want folks to use a blog post as a source of medical advice. But, last week I read a heart-wrenching Facebook post from Villabos Rescue Center (think Pitbulls and Parolees) about the last hours of a surrendered dog infected with heartworms. It is hard to imagine that most dog owners would deliberately cause their dog this kind of harm. I have to believe that many dog owners just don’t have the information they need to make informed choices about their dog’s health. So…here I am, telling my story in hopes that one less dog gets infected.

I adopted Gem last June from a local rescue that pulls dogs from overloaded shelters in southern states. I was a responsible pet owner–I had her tested and started on prevention almost immediately. End of story, right?

In March, Gem suddenly started to act lethargic. It was such a deviation from her normal behavior that I took her to my Vet Clinic. They determined that she had suffered a liver insult (of unknown origin), prescribed medications and told me to bring her back in a few weeks for follow up blood work. Out of sympathy I think, the Vet Tech suggested that I include her yearly heartworm test in the blood work. It wasn’t due for several months, but it would save me money. I was grateful for the price break, but was devastated when the test came back positive.

Like many adopters, I understood very little about heartworm transmission or the course of the infection. I knew that southern states have a higher incidence of infection than we do up north, given that the climate is mosquito friendly most of the year. I knew that while many veterinarians recommend prevention year round, many northerners only give it in the winter months. The disease, if left unchecked, results in a very painful death for the dog.

What I didn’t understand is this: from the point at which the infected mosquito bites your dog, it takes 6-8 months for the larvae (called microfilariae) to mature to the point that the dog tests positive. So,though Gem tested negative in June, she had most likely, been infected prior to her journey north. The American Heartworm Society recommends that adult dogs, not previously on heartworm prevention should be tested prior to starting heartworm prevention and at 6 and 12 months after that.

The other thing I didn’t understand is what heartworm preventative actually does. Heartworm preventatives don’t repel mosquitoes. They don’t stop the infection from occurring. Preventatives clear the body of the larvae that may have made it into the dog’s body in the past month. This is why your dog’s pills may come with little heart stickers to put on your calendar. It is really important it is to give heartworm preventatives on a consistent schedule.

Gem is now halfway through her 6 month journey through heartworm treatment. It has been incredibly hard on both of us. The injections are very painful and require high levels of supervision afterward to monitor the dog’s reaction to the treatment. Her activity level must be severely monitored and restricted, despite the fact that she thinks she is ready to run, jump and play. Crate restriction is a terrible experience for a dog who needs lots of regular exercise to stay balanced. The treatment itself can be up to 10x more costly than a year’s supply of preventative.

She will, most likely, be completely healthy when all is said and done. We caught the infection in its’ early stages. I still worry. I worry that something will go wrong. I worry what 6 months without public access training will do to her chances of becoming a service dog. I worry about paying for the treatment.

If you have made it to the end of this post, these are the pieces of information I hope you will take away from it:

  1. If you are taking an adopted dog in for their first heartworm test, ask your Veterinarian whether or not they recommend testing again in six months. If they do, ask the clinic to send you a reminder.
  2. Pay attention to dates. Use the little heart stickers on your calendar, if needed, so that you don’t accidentally give the preventative late or not at all.
  3. If you feel that you can’t afford testing or preventative, shop around until you find something you can afford.
  4. Look into health maintenance costs before you decide to adopt. Know whether or not you will be able to afford the costs of caring for your dog.


Sometimes old sayings are worth listening to….

“An ounce of prevention IS worth a pound of cure”.