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It's Gross-Thirty! Let's Talk Heartworms!

Whether you're a pet parent or not, you're no stranger to the word "heartworms." It sounds kinda gross, but you're probably able to brush it off fairly quickly, since you've never really understood what heartworms are... or if they're even real. They could be some tiny little microscopic organisms that cause no "real" harm to a pet, because you've never heard of someone's dog or cat dying from heartworms. Heck, you might even think it's a made-up condition to guilt pet owners into paying a little more to keep their beloved animal healthy. Well, wrong, wrong, and wrong. And by now, you've probably already seen the first picture and said, "Ewww, groooosss!" Spoiler alert. It's disgustingly gross and life-threatening, but totally avoidable.

What is heartworm disease?

According to, it's a serious and potentially fatal disease caused by foot-long...yes, FOOT-LONG WORMS that live in the heart, lungs and associated blood vessels of affected pets, causing severe lung disease, heart failure and damage to other organs in the body. Heartworm disease affects dogs, cats and ferrets, but heartworms also live in other mammal species, including wolves, coyotes, foxes, sea lions and—in rare instances—humans.

Do I have your attention yet? OK, I'll keep going.

How are heartworms transmitted?

Mosquitoes. Ugh. It seems like everything comes from those pesky little things, but they certainly play an important role in the food chain. In a nutshell, a mosquito will take the blood from an infected animal, fly to a vulnerable animal, and you can probably guess the rest. It takes about 6 months for heartworms to mature from larvae to adults, and they have a lifespan of about 5 to 7 years in dogs and 2 or 3 years in cats.

How bad are heartworms, really?

Heartworm disease can affect the heart, lungs, kidneys, and liver. The adult worms can cause blood clots in the lungs, and heart failure. Heartworms can also cause liver or kidney failure. Although it's rare, an animal can even die suddenly if exposed to a large number of heartworm larvae at once.

How will I know if my pet has heartworms?

If you're waiting for symptoms, I have VERY bad news for you. By the time your pet shows symptoms of heartworm disease, there could be a significant infestation which may require emergency surgery. The best way to keep your pet safe is a routine (usually monthly) preventative medication that kills heartworms in the larval stage. Heartworm preventatives will NOT kill adult heartworms, so it's important to stay on track with your pet's preventative plan.

What if I miss a month?

It's not the end of the world, but it's obviously not an ideal situation either. If your pet has become infected during the time that you missed a heartworm dose, test results will not show as positive until 6 months after the initial infection. Your vet may also suggest annual heartworm tests to make sure the medication is doing what it's supposed to, and your pet is staying free of adult heartworms. If you catch the worms an early enough stage, treatment is available, but it's definitely cheaper to remember.

The bottom line...

Heartworms are real, and they're a serious threat to our pets. It only takes 51 days for a larvae to reach the stage of growth which cannot be effectively eliminated by preventives. Whether you choose a pill, a spot-on topical medication or an injection, please help keep all of our fur-babies safe by sticking to a schedule.



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