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Dog Heartworm Disease - Heartworm Disease and Treatment For My Pet

What is heartworm disease and how can it affect your dog?

Heartworm disease is just that; a worm that ends up in your dog's heart. It's transmitted through mosquitoes. They have complicated life cycles, but the small microfilaria lives inside of the mosquito. When they bite your dog, they inject the microfilaria into the skin, and it eventually gets into your dog's bloodstream. Over the process of months and months, they develop into adult worms in your pet's heart.

Dr. Tiffany Hart
Stanislaus Veterinary Group

What are some of the signs that would indicate my dog has heartworm?

By the time your dog starts exhibiting clinical signs, it tells us that there are most likely adult worms in your dog's heart. Exercise intolerance, coughing, vomiting, and lethargy can be evident. It can vary, but you will see exercise intolerance and coughing most likely related to heart disease.

How soon should I bring my dog in to see a veterinarian for heartworm preventative?

It's never too early. At Sylvan Veterinary Hospital and Stanford Veterinary Center, we start our patients on heartworm preventative as early as four months on their last visit from their puppy package. I would recommend that any dog before six months of age start on some sort of heartworm prevention. For those who are not on heartworm prevention, it's never too late to visit your veterinarian, get tested, and start on heartworm prevention at any time.

How would my vet diagnose heartworms in my dog?

There are different kinds of testing. The heartworm test that we run in-house that you get on an annual basis is a SNAP test which is a couple of drops of blood. What that's looking for is adult worms in your pet's heart. If that comes up positive, it means that your dog is already infected with heartworms, and they need treatment.

How does my dog's lifestyle affect the risk for heartworm?

The more active you and your pet are, the more exposure you're going to have to mosquitoes. But even indoor pets have been known to acquire heartworm disease. There are mosquitoes everywhere, especially in the Central Valley, where there's so much agriculture and stagnant water. We see heartworms throughout the whole year. Dogs are not the only ones that are susceptible. Cats are susceptible too. Although it'd be less frequent, it's still worth having cats on heartworm preventative as well.

How often should I test my dog for heartworms?

We recommend yearly or annual testing at the same time as your wellness exam. Patients that come in and are exhibiting clinical symptoms that may be attributed to heartworm disease will get tested again, just to rule that out. But, at least once a year in our environment, we test them for heartworm disease.

What type of preventatives are available?

There are all sorts of different preventatives. You and your veterinarian should discuss this as each product is tailored towards a different situation and a different lifestyle. Some products have flea, tick, heartworm, and intestinal parasites. There are injections for heartworm only that can last up to a year. Those are very convenient. We also have products like Tri-Heart or Heartgard that treat heartworms. It's best to pair up with your veterinarian and discuss the best treatment or preventative for your pet.

If my dog gets diagnosed with heartworm disease, what's their life like?

Unfortunately, once diagnosed with heartworm disease, usually by our in-house testing, it means that they already have adult worms in their heart. The treatment consists of multiple stages. It's a very long course of treatment that takes us just under a year. It's a painful treatment that has a lot of side effects. It's expensive, and we don't recommend even having to perform a treatment. They will be hospitalized and will have to get multiple injections to try and kill off those adult worms in the heart. They have to be on extreme restriction for months at a time because it's dangerous for them to move around while they're getting this treatment.

You can imagine your dog who doesn't feel good, also being on medications like steroids that don't make them feel well. They're locked in the house, they're crated, they're receiving injections, and they're on steroids. They can't go to the dog park, go on dog walks, or go to the groomers. This is for 90 days at a time. So, prevention is worth it. This disease can be fatal if it's not detected. Even if it is detected and we perform successful treatment, sometimes it's so advanced that the dogs don't make it through the treatment.

Even if they successfully make it through the treatment, they can still succumb to heart disease later on in life because of the pathological changes that these worms have created in their heart, being in there for so long. So this is just one of those diseases where if it's not detected and treated, it's fatal. It's not worth not treating your pet. My recommendation, after seeing these pets get treated, is to put your dog on heartworm prevention year-round. In San Joaquin Valley, we have mosquitoes all the time, so keep your pet as safe as possible.

Have you noticed an increase of heartworms in our area?

I have. About 15 years ago, we didn't think that we saw or had heartworm here. If we saw heartworms at the hospital, it was from the migration of animals from other places like dogs that came over from hurricane Katrina or came up from Mexico. They had it high up in Placerville and Sonora, but it migrated here. The majority of our pets that are testing positive at Sylvan and Stanford Veterinary Center are local and they haven't traveled. They haven't gone anywhere. They're picking up these mosquitoes in their own backyard when they go out on the wet grass in the morning. It's here, it's real, and you need to take action to keep your pet safe.

If you have any more questions, you can visit our website where we have reference pages on heartworm disease. If you'd like to have your pet tested for heartworm, please call our office. Sylvan Veterinary Hospital, 551-4527. Stanford Veterinary Center, 527-8844.

Dr. Tiffany Hart
Stanislaus Veterinary Group

Good morning. I'm Dr. Tiffany Hart from Sylvan Veterinary Hospital, and I'm also speaking on behalf of Standiford Veterinary Center. Today I want to talk about the importance of running your annual fecal exam and the health concerns surrounding intestinal parasites. Our hospitals don't just recommend running a fecal sample when your pet has diarrhea or when they're having intestinal troubles. We do that as part of our annual exam every year. Sylvan Veterinary Hospital alone runs over 2,500 fecal samples a year, and we have seen up to 20% positive results. On average, Modesto dogs themselves have about a 15% positive rate for some form of intestinal parasite. The concern is that most of these can be very debilitating to your pets. They can cause anemia and skin disease, and some parasites migrate through the liver and the lungs. Not just to mention the obvious, which is GI discomfort, vomiting, and diarrhea.

They are so endemic in our area, but some of them can be transmitted through the milk and the placenta. So it's not uncommon for us to have puppies come in that are already infected with intestinal parasites upon presentation, not to mention puppies and dogs in general lick everything. They put everything in their mouth. It's as simple as getting some dirt on their paw and licking it off their feet when they're self-grooming, and they pick up intestinal parasites. Some are transmitted by flies, and there are intestinal parasites, or I should say heartworm disease, that are transmitted by mosquitoes. So it's everywhere in our environment, and our dogs go so many more places now. They're at the dog park; they're at doggy daycare drinking out of the same waters; they're drinking out of the gutters on our walks. The prevalence here is really high.

Our recommendation is to have your dog's fecal samples scanned for intestinal parasites at least once a year. If they're experiencing GI discomfort or chronic diarrhea, we want to do that more frequently. The other concern is that many of these diseases can be transmitted to people. Children are the most likely to be infected because they're playing with their pets on the ground and putting their hands in their mouths, and this can cause serious diseases. Roundworms can cause ocular problems. Hookworms can cause skin diseases in people. Giardia, which is the most common parasite we see in this area, can cause chronic intestinal problems.

So when we recommend that your pet has an annual intestinal parasite screen, it's not just to protect your pet's health but also to help protect the health of your family. If you have any questions or concerns, do not hesitate to call one of our hospitals, or you can go to our website,

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