April 5, 2019
Written by: Danielle Matise
If you’ve ever owned an animal in Texas, you’ve *probably* heard about heartworms and *hopefully* give your pets regular heartworm protection. But how much do you *really* know about these invisible intruders? Are they actual worms? Are they contagious? Is heartworm disease REALLY that bad? We’re breaking down the most important information that you need to know, right here:
1. As if you needed another reason to hate them, you can blame mosquitoes for spreading heartworms. The life cycle of heartworms starts when a mosquito bites an infected animal and ingests the larvae…yum.
Then the process gets a little strange. The larvae actually mature to the next life stage while inside the mosquito, and when the mosquito bites another animal, it transmits (or “rehomes”) the developed larvae. While living in their new host, the larvae will go through two more growth stages until they mature into adults, settle into their new home, and begin to reproduce live young called microfilariae. It sounds like a happy ending for these parasites, but it’s just the start of severe heart problems for your pet.
2. Yep, heartworms really do live in the heart. When a pet is first infected, the larvae grow and molt under the skin where the bite happened. From there they begin to travel to the muscles of the chest and abdomen, and eventually enter the bloodstream where they are carried directly to the pulmonary artery.
As adults, heartworms are thread-like and grow to be 12 inches long in full maturity (good luck eating spaghetti ever again). This causes serious damage to the heart, lung vessels, and tissues, and typically results in fatal congestive heart failure within 5-7 years. Symptoms such as weight loss, coughing, a fluid-filled abdomen, and exercise intolerance typically won’t show up until it is already advanced.
3. Watch out for false negative heartworm test results–they happen more than you might think. Let’s revisit the life stages we just talked about. The entire life cycle–from microfilariae babies to adult spaghetti-worms–takes 7 months.
Standard testing can detect antigens (the body’s way of signaling an intruder) that are released due to adult heartworms, but it cannot detect the other life stages. This means that if a dog is infected and tested within the first 7 months, chances are that the test will be negative because the worms have not yet matured. This is why animals under 7 months or those who have not been on preventatives consistently should be tested 6 months apart for the first year.
4. Felines can get heartworms too, and when they do, it can be cat-astrophic. All jokes aside, cats are considered atypical hosts for heartworms compared to their canine counterparts. This means that when they are infected, the process is a little different…leave it to cats to do things their own way!
Most larvae do not survive in cats, so their lifespan is much shorter. However the ones that do survive can often migrate to other parts of the body, including the brain, and there is no effective treatment. The infection rate for cats is only 1-5% compared to dogs in the same area, but putting them on heartworm prevention is still recommended to take away any risk of infection.
5. Texas is in the Top 5 WORST states for heartworm disease. Everything is bigger in the Lone Star State…including the rate of heartworm infection. Our warm, humid environment is prime real estate for mosquitoes to transmit the disease successfully.
In Harris County specifically, the weather never REALLY stays cold enough (aka 57°F) to halt the development of heartworms, leading to one of the highest incidence rates in the state. Unfortunately every heartworm positive dog in the area also increases the risk of infection to healthy dogs.
6. Prevention is always cheaper and easier than treatment. The good news about heartworm disease is that it’s actually preventable! Puppies and kittens should be started on heartworm protection at their very first vet visit. [Psst: You can even order it online and have it shipped to your door!] It should be given every month for the rest of their lives, and they should also be tested annually.
While successful treatment options do exist for heartworm disease (and you can read more about them here), the cost of treatment is the equivalent of several YEARS worth of heartworm prevention! Not to mention giving a tasty treat or applying a topical solution is much easier for you and your pet than having to follow months of rigorous treatment protocols.
Now that you’re an expert on heartworms, head over to our Facebook page or stop by the clinic to play “Guess How Many Worms”! You could win one of two prizes for a 6 month supply of heartworm protection! For additional questions about heartworms or to set up a consultation, please give our team a call at 713-659-0650 or schedule a visit online.