You’ve probably noticed in recent years that there has seemingly been more mosquitos inhabiting your work and living spaces. Maybe you’ve been hearing that annoying buzz around your ears a bit more often, maybe you’ve been experiencing more irritating bites during the summers. Well, you’re not wrong. Recent data has shown an exponential increase in mosquito population throughout the United States. Subsequently, it makes sense that diseases spread by biting mosquitos, in people and pets, has shown a huge uptick as well. Chief amongst these diseases in pets is Heartworm Disease, a scary, potentially fatal, expensive to treat disease transmitted by mosquito bites. This disease, and mosquitos, have spread enough that testing and prevention has become core to veterinary care, even in places such as California, where mosquitos and the diseases they transmit have previously been extremely rare. So today I want to spread some awareness and education about this scary disease, and how to best help your pet from getting it. First things first:
What is heartworm disease?
Heartworm disease is a potentially fatal, but preventable infection caused caused by long, slender parasitic worms (Dirofilaria Immitis) that can reach up to 12 inches in length and can infect dogs, cats, and ferrets. These parasites are transmitted from infected pets to other pets by the bite of mosquitoes. Once arriving in the new host, the worms grow larger over several months and will live in the right side of the heart and large blood vessels of infected pets. Once there, the worms are capable of causing substantial damage to the heart and lungs before the pet shows any signs of disease. When there is an overload of worms in these vessels, they can blog bloodflow in the heart and important vessels, leading to the death of its host. Fortunately, heartworm disease is a disease that is entirely preventable!
Is my pet at risk?
Heartworms primarily affect dogs, but infection in cats is common in many areas and is on the rise. Unfortunately heartworms in cats are generally more dangerous because it takes fewer worms to cause problems and treatment is more risky.
What are the signs of Heartworm Disease?
Because of the amount of time it takes for the worm to mature, symptoms of heartworm disease typically don’t show until the disease has progressed severely. Symptoms of this disease include:
- exercise intolerance
- excessive panting
- difficulty breathing
- chronic vomiting (especially in cats)
Pets at highest risk are those that go outdoors in areas with mosquitoes, however, indoor pets are not safe from heartworms since mosquitoes can get inside as well. Heartworm disease exists throughout the country as mosquitoes can travel in the wind many miles from a water source. One bite from an infected mosquito can lead to the death of a pet and no pet is completely safe.
Testing for infection? How is Heartworm Disease Diagnosed?
I recommend that dogs 6 months and older be tested annually for heartworms. The earlier an infection is caught, the easier and safer the treatment is. I also recommend testing any pets that are experiencing any of the previously mentioned symptoms. A quick in-house blood test to screen for the infection is available at most veterinary clinics. For patients that test positive, additional testing (ie. blood tests, ECG, xrays, or urinalysis) may be necessary to determine the degree and damage of the infection.
How is Heartworm Disease Treated? What is the Prognosis?
Treatment for heartworms can be risky, expensive, painful, and does not come without complications. That's why I recommend year-round protection! The prognosis for patients with heartworms varies, depending on the degree of damage associated with infection. Animals infected with heartworm go through a series of veterinary visits for bloodwork, x-rays, potential hospitalization, and a series of injections into the back muscles as well as oral medications. Additionally, dogs must be kept calm, quite, activity restricted, and rested during this time to avoid the side effects of the breakdown of dying worms within the bloodstream. Supportive therapy is given to decrease inflammation, aid breathing, and decrease the risk of complications. Patients that survive this disease are not immune and still need preventive following treatment! If the worms damage the heart, the pet may need lifelong supportive medication and therapeutic diets, and heartworms can also damage the kidneys as well, causing long-term kidney disease.
How is Heartworm Disease Prevented? How Do I Protect my Pet?
Prevention for heartworms is safe, easy, and much more affordable than treatment. The best way to reduce your pet's risk of infection is to administer a heartworm preventative year round available in three safe, effective forms:
1. an injectable preventive for dogs that lasts six months
2. an oral tablet to give your pet once a month
3. a topical form of preventive is also available
Any type of preventive should be used for the life of your pet. Your veterinarian will recommend the form of heartworm preventive that is appropriate for your pet. Because they may already be infected, it's important dogs over 6 months of age to have a blood test before starting heartworm prevention.
Did you know?
Mosquitos are the only known carrier of heartworms and only female mosquitoes can transmit the infection to dogs and cats? So it's no surprise that unprotected outdoor dogs are four to five times more likely to be infected than indoor dogs. However, even indoor dogs can get heartworms, so every dogs and cat should be on year-round preventive.
Limiting exposure to the number of mosquitos in the environment can help. You can do this by getting rid of any standing water, decreasing the amount of grass and vegetation in the yard, and using mosquito traps. Though, avoiding mosquitos entirely is obviously impossible, so the only way to prevent heartworm infection is by routinely giving your pet the preventive treatment.
Talk to your local veterinarian about which preventative is the best choice for you and your dog, remember “an ounce of prevention is worth a pound of cure.
For more information about heartworm disease, please visit the American Heartworm Society https://www.heartwormsociety.org/ website.
About the Author:
Dr. Zonram Liao D.V.M. is a Southern California native, and earned his undergraduate degree from University of California, San Diego before obtaining his veterinary degree from Ross University School of Veterinary Medicine. He is not only a firm believer in the use of supportive care supplements to improve the health and happiness of his patients, but also is a strong advocate of the benefits of preventive care medicine for his patients as well. During his free time, Dr. Liao enjoys spending his time outdoors fishing and hiking, playing basketball, watching movies, cooking, traveling, and trying new foods.