8 Heartworm Facts to Know for Heartworm Awareness Month

8 Heartworm Facts to Know for Heartworm Awareness Month

As April is Heartworm Awareness Month, Crate Escape Pet Care has assembled a few facts you may not know about these heartworms. We often hear about these persistent little nematodes every trip to the vet, but not many know the finer details involved in this life-threatening infection for your pets. Read the following eight facts to know before you head out for your pets’ yearly exam:

1. Your Pet Can Get Heartworms at Any Time and Any Place: While many pet owners save a few bucks by only using heartworm prevention for those pets who go outdoors in the warm months, cases of new heartworm are reported all year round in all climates3. Residents of Alaska will be surprised to hear they are just as likely to need heartworm prevention as those in Florida. Mosquitos are easily blown off-course by winter storms from areas where they live year-round to colder climates. For 100% fail-proof prevention, use preventative care in the winter and for indoor pets, too.

2. There Is No Treatment for Cats, Only Prevention: While cats are just as likely to contract heartworm as any other pet, there is no approved treatment for if a cat gets heartworms3. This may be because cats often show no symptoms of heartworm infection until they are seriously ill, as even one adult heartworm can be fatal in such a small body. Preventative care is the only way to keep your cat safe from heartworms.

3. Heartworms Carry Potentially Fatal Bacterium: If your pet is diagnosed with heartworms, it is not always the parasite that will be fatal. Heartworms carry a particular type of bacteria called Wolbachia2. This bacterium causes inflammation of the blood vessels and is released in greater numbers when the heartworm dies. It can cause organ damage and prevent blood circulation. This is why your veterinarian will prescribe antibiotics as a first step when treating heartworms.

4. Mosquitos Are Natural Carriers, But Humans Can Get Them Too: Most pet owners know that heartworms are carried by mosquitos, but did you know that mosquitoes usually pick up heartworm eggs from wild mammals like foxes and coyotes3? After they drink the blood of an infected animal, the eggs mature into larvae inside the mosquito, which are then transferred onto the skin of the next animal they bite. The larvae get into the animals’ blood system through the bite of the mosquito, and then grows up into an adult to start the process all over again.

While heartworms live best in our furry friends, there have been rare cases of humans getting heartworms, but they generally prefer to live in our eyes and lungs instead of our heart4. Just another reason to keep these worms very far away from you!

5. Dogs Will Show No Symptoms Until the Infection Is Severe: Dogs rarely show symptoms of an infection until there are many worms in their system. An adult dog can sometimes carry over two hundred of these foot-long worms, and even thirty adult worms may not cause any symptoms (depending on the size of the dog)3. Only when there are enough worms to cause circulation problems will dogs become tired, reluctant to exercise, lose weight, and develop a mild cough.

6. Treatment Is Long-Term and Not A Sure Cure: The heartworm treatment for infected dogs, an arsenic based program of injections, can take months to kill all the worms in a dog. As worms mature, they will continue to release eggs, which can mature after a treatment injection is given and release more eggs before the next shot. This can mean months of treatment and restricted exercise, a process that is often fatal unless the number of worms is very small.

7. Yearly Testing for Heartworms Is A Necessary Step: You may be puzzled when your vet insists on yearly testing even though you give your pet heartworm prevention every month. Sometimes pets can be infected unexpectedly, like if they vomit up the prevention pill and are able to be infected before the next dose. If they somehow are infected with even a few worm larvae, using preventative medication can kill your dog. If your dog is infected with heartworms, it is important to work with your vet to come up with the best treatment for them and to proactively test before treatment.

8. Topical Heartworm Prevention Has Tested Most Effective: In a 2011 small study, researchers tested four different applications and chemicals used to prevent heartworm in beagles, and found that topical imidacloprid was the only kind to have 100% effectiveness1. The other types tested, chewable and other types of skin treatments, were only about 95% effective. While any type of heartworm prevention is good, imidacloprid (known as Advantage Multi) is the most effective.

Now that you know some interesting facts, check with your local vet office to see if they are running special pricing for heartworm prevention. With Spring here and your pets’ health to keep in mind, this could be the most important conversation you have with your vet during their yearly check-up!

By Lauren Pescarus

1 Blagburn, B., Dillon, A., Arther, R., Butler, J., & Newton, J. (2011). Comparative efficacy of four commercially available heartworm preventive products against the MP3 laboratory strain of Dirofilaria immitis. Veterinary Parasitology, 176(2-3), 189-194. doi:10.1016/j.vetpar.2010.12.049
2 Becker, M. (n.d.). Heartworm Treatment for Dogs: What You Need to Know. Retrieved March 26, 2018, from http://www.vetstreet.com/dr-marty-becker/heartworm-treatment-for-dogs-what-you-need-to-know
3 Heartworm Basics. (n.d.). Retrieved March 26, 2018, from https://www.heartwormsociety.org/newsroom/background-information
4 Douglas, N. (2017, September 30). Why Don’t Humans Get Heartworm? Retrieved March 26, 2018, from https://healthyliving.azcentral.com/why-dont-humans-get-heartworm-12313667.html