What are heartworms, and how do they affect dogs?
They're a parasite that's carried by mosquitoes, and the parasite likes to live in the right side of the heart. Consequently, it causes damage to the lining of the heart. The parasites can migrate into the lungs and cause damage to the lining of the lungs. The adult heartworms lay little heartworms called microfilaria that can also cause damage to the microvasculature in the dog's kidneys, eyes, and things like that over time.
How does a dog get heartworm?
It's carried by mosquitoes. A mosquito bites an infected animal like a coyote, wolf, or another dog. The parasite undergoes some development in the mosquito's intestinal tract, and then the mosquito gets a new blood meal. The parasite passes from the mosquito via that blood meal into the new host, which is the dog. The parasite undergoes some tissue development and migrates to the right side of the heart, setting up camp there, so to speak.
What are the signs of heartworm in a dog?
Sometimes there are none. It depends on the number of heartworms and how the dog reacts to them. Other times, there can be exercise intolerance, coughing, weight loss, and you can just tell that something's not right. Again, it depends on the quantity of heartworms, what we call the heartworm load, and how the dog reacts to them immunologically.
How will a veterinarian diagnose heartworm in a dog?
We draw blood. The test that we use here detects an antigen that's only present in the female heartworm, so it's a pretty sensitive test. Is any test perfect? No, so we can miss some things. Before this test came out, we would draw blood and actually look for the microfilaria via filter. Like I say, just like everything else, technology has advanced and moved on.
What happens if my dog tests positive for heartworms?
We're going to retest your dog using a different test just to confirm that that's the case. If that second test confirms that your dog has heartworms, then we'll talk to you about doing some blood tests, x-rays, EKG, and then the process of treatment, which involves medications. One of the ones we use is called Immiticide. It's been around for a long time. Those injections are given in the back, a series of three injections over a period of months.
What can I do to prevent my dog from getting heartworm?
The easiest thing is to get them on preventative, and there are a lot of choices. Heartgard is a once-a-month preventative that's been around forever. There's also Interceptor, Tri-Heart, a spot-on called Selamectin or Revolution, and an injectable called ProHeart 6 and ProHeart 12. As their names imply, they're given once every six months or once every 12 months, making it kind of foolproof. You don't have to remember to do it; it's already there, and it just does its thing.
Are heartworm preventatives safe for dogs?
Yes, as long as they're used at the right dose and proper intervals, you're going to be fine. For example, when you give Heartgard or Interceptor, the product does not stay in the dog for more than about 24 hours. It kills a certain stage of the heartworm before it can get to the heart, and then the drug is metabolized off. Obviously, if you were to grossly overdose, then you could have some problems. With ProHeart 6 and ProHeart 12, it's a timed release of the drug, and again, if used properly and dosed properly, you do fine.
What should I do if I forget to give my dog their heartworm preventive?
As soon as you realize you've forgotten—and I've done it—don't feel bad, just give it and then go back to your regular schedule.
How successful is the treatment for heartworms?
We use the three-protocol treatment: three injections of Immiticide, and it's about 98% effective. Again, nothing is perfect, but that's pretty close. There's also what they call a two-stage protocol, and that's about 90% effective. Like I say, I figure if you're going to do this, let's go for the gusto, and so we treat with three injections over a period of a couple of months.
If you have other questions and you'd like to reach out to us, you can call us directly at (402) 489-0501, or you can email us at staff@vhvet.com. But please do reach out, and we'll get back to you as fast as we can. Don't forget to follow us on social media Facebook, Instagram!