An occasional dog can have diarrhea, but it’s very rare. And with some of the topical products, the products placed on the skin, you have an occasional dog sensitive to the carrier or whatever it is in that topical product. That dog might have some itching and hair loss in that area. Again, that's pretty rare, though. These products are safe for the Collie breeds. You'll read about that sometimes, and people worry about that. Sometimes, Collies have trouble with certain medications, but these products are all very safe.

The heartworm preventatives are 95% effective, if not more. There are a few cases of resistant heartworms that have become more recent. They used to be 100% effective. Now, they're about 95%, I would say. And that's still pretty good.

Also, some people are under the misconception that they don't have to give preventives in the winter. That's not true. Especially here in North Carolina, we have temperatures where mosquitoes can replicate and infect dogs all year. We recommend year-round treatment in most places in the United States now.

There are many products out there. They're called macrocyclic lactones, that's the class of medication, and they're very safe monthly pills. And many of them treat intestinal parasites as well. There's also an injection called ProHeart. There's ProHeart 6 and ProHeart 12 for people that have trouble remembering to get pills monthly. And there are topical products—Advantage Multi and Revolution are a couple of them out there that we apply topically to kill the worms. Many of these products are also effective against intestinal parasites, and some of them are combined with flea and tick products. The product we choose depends on the individual dog's lifestyle and the owner's needs.

In the cases of advanced heartworm stages, where the dog is in heart failure or has portacaval syndrome, a terrible complication dogs can get with heartworms; we treat those dogs differently. They need to have their heart failure treated, and sometimes, they require surgical removal of those worms, and it carries a very poor prognosis.

Yes. Dogs can be treated for heartworm, and we stage dogs. There are various stages. There are classes of heartworm disease. The dogs are classed based on the changes to the heart and lungs, X-rays, blood work, and the dog’s symptoms. The class one and two dogs, which are earlier stages, tend to do pretty well. We start the heartworm preventative. We start that antibiotic we had talked about before, and then we allow a couple of months for those things to work. It sounds crazy that we would wait that long, but we also have to wait for immature worms in the body that can not be treated with conventional treatment. They're not susceptible to conventional treatment until they become adults. So, we got to wait for those to mature, and that takes a couple of months. We also need dideoxy cycling time to work to destroy the symbiotic bacteria that live in the heartworm.

And then, that antibiotic is also an anti-inflammatory in the lung, so dogs do so much better if we slowly prepare them for treatment.

About two months later, we give an injection called immiticide or Melarsomine, killing adult heartworms. We give it in the muscle of the back. But not one injection is effective, so we have to give another set of injections a month after that, so heartworm treatment is very drawn out. We have to kill these worms slowly. We can't kill them too quickly because, often, we'll have fatal pulmonary thromboembolus. Dogs do not do very well. They'll have many complications from treatment if we do not treat them slowly and prepare them to be treated.

The ELISA test is very accurate, but on occasion, if it's, say, a really weak positive, we call them, or it's just not a really strong positive, if there's any doubt about this dog's heartworm status, we will take more blood and send it to the lab. And we will do another test to confirm. If we have microfilaria (baby heartworms) circulating in the dog's blood plus a positive test, most of the time, you can be pretty assured that that dog does have adult heartworms.