I remember the first time I saw heartworms; yes, they are big, real and visible! My college summer job was at the local veterinary clinic. I worked mostly with the small animal vet “Doc” as he was often called by clients. This clinic also had two large animal vets. For my readers whose imaginations jump to elephants and whales, scale back to cows and horses. Doc was the senior vet nearing retirement. He did his best to discourage me from entering the profession. If a case came in infected with maggots, he handed me the ether filled spray can to anesthetize the maggots and said “start picking”. That is a blog story for another day! Well, at this clinic on a shelf in the lobby was a glass jar; the kind you see now that look so elegant filled with candy or seaglass on everyone’s coffee table. The difference, this one was filled with formaldehyde and the heart of a dog that had died from heartworm disease. That means, dead worms were entwined around the heart and coming out of the major vessels of the heart. I couldn’t believe how big they were! Doc said “clients need to see what is killing their dogs or they don’t care”. At the time it was preventable but the medicine had to be given daily and a lot of dogs weren’t given it or they were not given it consistently.

Well, needless to say, all of old Doc’s antics didn’t dissuade me from becoming a veterinarian. Even though he thought I should go into human medicine, when it came time to apply to vet school, Doc wrote me a great recommendation and I started vet school fall of 1989 at Michigan State University. I spent the first 3 years mostly in front of a book or in a lab. So my knowledge of heartworm, its life cycle, its intimate relationship with the mosquito, the medications to prevent and treat, were all by reading or lectures. The image of the heartworm in the jar was still in the back of my mind but I had no glimpse of the nasty worms, that is until my final and 4th year of vet school. I was rotating through the different specialties and cardiac rotation was next. The doctor (a veterinarian cardiologist) had an uncanny resemblance to my “Doc”; flat top grey hair, stocky stature and spent most of the day discussing all of the world’s problems as we examined patients and explored the dynamics of the heart. One of our cases was a boxer in congestive heart failure, the cause, heartworm disease. Heartworm treatment at the time was a form of arsenic given intravenously. He wasn’t a typical heartworm case though, he had massive numbers of worms and medical treatment alone would surely kill him. If there are high numbers of worms and they are killed by the medicine all at once, the body may not be able to break them up and remove them, blockages are likely to occur. There was a lot of discussion in the hospital on how to save this sick guy, the cardiologist said his best chance was to do open heart surgery and remove as many worms as they could, then follow up with the medicine to kill any remaining worms. So, my second look at real heartworms was in a surgery suite. The white wiggly worms were alive and moving being removed from this poor boxer’s heart. The number of worms removed I can only guess, but like any good story the number grows as I age! The happy ending we hoped for occurred, he lived. However, like most dogs that become infected with heartworms, he had some permanent heart disease and did have to stay on medications for life to help his heart function.

I really hoped after that day I would never see an adult heartworm again. Fate would have it in the summer of 1998 my husband and I made the migration north by purchasing an existing practice in Traverse City. We named our dream Long Lake Animal Hospital. Guess what we found on a shelf in a cupboard, a lovely glass jar filled with formaldehyde cradling a heart full of heartworms! It is funny, seeing those little beasts this time actually made me smile thinking of my two mentors that have since passed. Did the veterinarian who owned the practice before us get it off craigslist from old Doc before he passed? Was she of the belief our clients won’t understand the seriousness of heartworm disease unless they see it too?

​Prevention of heartworm disease is much easier today, a chewable treat once a month will do it for both dogs and cats! Unfortunately, if not prevented the disease is still as devastating. It still requires a form of arsenic (caparsolate) to kill these adult worms in the dog. Our cat friends cannot be treated if they have heartworm disease because they can’t survive the caparsolate. The heartwormsociety.org is a great source for more information on heartworm disease, incidence, treatment and prevention. As to the jar at our office, it’s sitting on the shelf still in the cupboard. I mostly pull it out to torment my young vet wannabes in honor of Doc. I don’t discourage anyone though because I know I am in the best profession and even a day of maggots is a good day!

My best,
Dr. Lisa LaCross