Last year I wrote an entry about heartworms not just being a problem in dogs (if you weren't here then, read it right here). I swear, I'm starting to get extremely paranoid about heartworm disease. In the past two weeks, I've had five different dogs that have tested positive. That's more than I think I've ever had in such a short period of time. Today it got worse. I had my first heartworm positive cat in 12 years of practice.
I've known that cats can contract heartworms since veterinary school, so it didn't totally surprise me. I've also tested cats over the years, and have always had negative results. But this one was most definitely postive. Want to know why he came in to see me? Sporadic vomiting for the past three weeks. And as surprising as it may seem, vomiting is one of the leading signs of heartworm disease in cats.
Here's a quick review of heartworms in cats. Felines are many times more resistant to heartworms than dogs, and so are much less likely to get it. However, when the become infected, they had fewer worms so it's harder to detect. In an average infection in a dog there may be 30-50 worms. In a cat it may be 1-3. Even if we find it, we're still a bit up the creek. There is approved treatment protocols and medications for dogs, but not for cats. So cats are less likely to contract heartworms, but if they do it's harder to find and we have no way of treating it.
The worms live much shorter lives in cats than in dogs. So the goal is usually to control any symptoms and hope that the cat outlives the worms. This isn't a very satisfying answer to be able to give a client, but I had to have just that kind of conversation today. Thankfully the cat doesn't seem to be too severely affected, so we're hopeful for a good outcome.
Remember how I've been up in arms about owners not putting their dogs on prevention? Now I get to do the same thing for cat owners. The larval heartworms are carried by mosquitoes, so even indoor cats are susceptible. Spend the money and put your cats (and dogs) on heartworm prevention! And if your cat is vomiting and your vet recommends a heartworm test, please do it!