The weather is finally getting cold here in southeast Missouri. Motorcycle riding will be reduced to the bi-weekly ride to "blow out the cobwebs"– twenty minutes of freezing while wishing I was home already. You’d think the mosquitoes would all be gone, but they are still flying around inside my house. We live in a swamp… a drained swamp, yes; a reclaimed wet-land, even… but still a swamp.
Back when the only heartworm preventive drug was DEC (diethylcarbamazine), it had to be given every single day, or it didn’t work. So you’re going to feed the dog every day, you pet it every day — just give it the pill while you’re at it (or the liquid, or the chewy treat). That’s fine for dogs that don’t object to being medicated. For those that do object, however, it was a real ordeal. If your dog puts up a big fight every time you have to give that once-a-month heartworm preventive, you can feel real satisfaction about a job well-done. Sure, it wasn’t easy, but you got it done: you did the best for your dog. Once a month, it feels good. Every single night of your life… not so good. People don’t get a dog so they can fight with it. People who had to deal with that would talk themselves into the notion that they could stop their heartworm preventive when the weather cooled off. It ain’t so, at least it ain’t so here in the swamp.
We have so many mosquitoes for so much of the year that we really have to give the preventive medicine year-round. With large-breed outside dogs, sometimes they still get heartworms, even so. You surely can’t skip months here and there and expect the dog to stay free of these parasites.
That’s why I was so surprised when taking the history on Max the Labrador Retriever three weeks ago. It was our first time to meet Max. He had suffered some bite wounds to the top of his head and his ears (ouch). His owner told me that he had been treated to clear out adult heartworms in 2005, but had not been taking the preventive medicine since then. WHOOPS! The heartworm treatment clears out the adults, but has no effect on the development of new ones. More mosquito bites will mean more heartworms, unless you keep the guy on preventive medicine (Heartgard 30, Interceptor, Sentinel, Revolution, etc.). "As soon as he gets over these wounds, we need to get him up to speed on the heartworm situation. He probably already has some new adult worms." Truer words were never spoken.
Today they found Max by the back door, stone dead. Post-mortem exam showed extensive hemorrhages throughout his lungs. He had more than 50 worms in his heart, plus worms throughout his pulmonary arteries. He didn’t die of heart failure, but from the damage the worms did to the arteries in his lungs. He drowned in his own blood. It was a sad day, and even sadder because it didn’t have to happen.