Cincinnati tops the list for heartworm growth

Heartworms are scary, and unfortunately, they're here in Cincinnati. We earned the dubious honor of being the city with the fastest growth in the country of new heartworm cases last month. You can't see them, and they can make your dog or cat seriously ill. Heartworms are parasites that live in the heart, lungs, and large blood vessels of dogs and cats. They are transmitted as microscopic larvae by mosquitoes. Luckily, there are effective ways to prevent your dog and cat from getting heartworms.

As you can see from these maps, heartworm disease is steadily spreading across the country, and unfortunately Cincinnati is now in the red zone.​ We'll get the next updated map in 2020.

How do you get heartworm disease?

From a mosquito. A mosquito bites an infected dog, and ingests baby heartworms, called microfilaria. She then carries these microfilaria to the next dog or cat, and infects the pet when she feeds.

Those heartworm larvae now spend 2 - 4 months migrating through the tissues of the new dog or cat, growing up into adult heartworms when they reach the vessels of the heart. Heartworms can grow to be over 12 inches long, and can live for 7 years inside your dog. The heartworm preventions are only effective during the first 2 months from infection by the mosquito. 

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What should you do?

Protect your dog and outdoor cat every single month with heartworm prevention.
Common tasty chewable brands include Sentinel, Interceptor, Heartgard, and Triheart. Topical heartworm preventions are also available for cats and dogs - Revolution and Advantage Multi. There are many options, and they're all just about equally effective at preventing heartworms from reaching adulthood as long as they're given monthly. There is even a long-acting injection, ProHeart 6, which provides 6 months of protection.

We can help you decide which heartworm prevention is the best for you. They are all slightly different in what other parasites they treat, but they are equally effective at preventing heartworm. But they all MUST be given EVERY SINGLE MONTH in order to work. Talk to us about which particular medicine is best for your pet's lifestyle. Once those baby heartworms become adult, they are resistant to the preventatives and your pet needs treatment for the disease.

How to diagnose heartworm disease:
A couple drops of blood is all it takes to check your dog or cat. ​Here at Montgomery Animal Hospital, we will also screen your dog for tick-borne infections with the same test. Check with your vet about which test is being run, since some tests screen for heartworm only.

How to treat heartworm disease:
Heartworm treatment is a long, arduous process for dogs. There is NO treatment for cats - we are limited to supporting their hearts and lungs as best as we can until the worm dies on its own, a process that can take years. While it's worth it in the end to save your pet's life and lungs, it's not a fun thing to go through. 

• The first step is staging the disease to see how much damage has been done - this requires bloodwork, urinalysis, and chest radiographs.
• A heartworm prevention is given under medical supervision to stop the spread of heartworm disease and prevent any more worms from reaching adulthood. Often steroids and antihistamines are used too to reduce the chance of allergic reaction when the microfilaria are dying.
• Next, an antibiotic is given for a month to eliminate a commensal bacteria, Wohlbachia, that supports the heartworms. Without this bacteria, the heartworms start to wither and are less likely to produce the baby microfilaria.
• A month later, the first dose of melarsomine treatment is administered to start eliminating the weakened heartworms. Here's where the danger intensifies. The injection kills some of the heartworms, and now the dog's immune system must digest the worms to get them out of the blood vessels. But if the dog runs, plays, or has any excitement that quickens the heart rate, those worm pieces can be thrown into the circulation and cause a fatal blood clot. This injection is painful, and we support the pets with pain relievers and use steroids to decrease inflammation as the worms die off.
• One month later, the next two doses of melarsomine are administered. The exercise restriction remains strictly in place for another 6 weeks to allow the immune system to digest all the worm pieces.
• Finally, 5 months after diagnosis, the dog is allowed to run and play again. Bloodwork in 6 months is needed to confirm that all the heartworms were eliminated, and if not, the process starts again.

warning - graphic photograph below

Don't let this be your dog's heart. Keep up with monthly heartworm prevention, and test regularly.