Spring has sprung and, with the balmier weather, the insect population has sprung along with this season. Among the most annoying pests is the mosquito, but this tiny insect is more than a pest because it can cause deadly or debilitating diseases in your pet. 

You have likely heard about heartworm disease, but did you know a single mosquito bite can cause this condition? Once considered a southern-state problem, the American Heartworm Society (AHS) has tracked heartworm infection in all 50 U.S. states and Canada. Mosquitoes are getting heartier and can easily overwinter in warmer climates nationwide, causing the disease to spread.

Fortunately, this deadly disease is preventable. Our Town & Country Animal Hospital team knows that accurate information about heartworm disease is vital to pet owners, so we’re presenting all the information you need about heartworm disease and prevention in pets.

Heartworm disease basics in pets

Heartworm infection is caused by Dirofilaria immitis, which finds its way into your pet’s body through an infected mosquito’s bite. Once the heartworm larvae—microfilariae—are transmitted to your pet, they reside in your furry pal’s bloodstream. In about six months, during which time they migrate to your pet’s heart and lung tissue, larvae mature into foot-long adult heartworms. Once the adults reproduce, the baby microfilariae travel back to your pet’s bloodstream, where they can infect another mosquito and, subsequently, another pet. 

Pets’ heartworm disease signs range from mild to severe. Dogs’ heartworm disease signs include lethargy, exercise intolerance, coughing, weight loss, rapid breathing, and collapse. Cats are rarely affected by heartworm disease, but they may experience wheezing, coughing, vomiting, rapid breathing, weight loss, and sudden death. Even with mild signs, the worms can severely damage heart and lung tissue, negatively affecting your pet’s quality of life.  

Heartworm disease diagnosis in pets

Veterinarians can diagnose heartworm disease in pets by performing a simple blood test that detects the presence of an antigen in the blood caused by female adult heartworms. A test is also available to detect microfilariae in the blood. X-rays or ultrasound testing are sometimes recommended depending on your pet’s disease severity. 

Heartworm treatment in pets

Unfortunately, heartworm disease treatment is expensive, time-consuming, and risky. Between 30 and 40 adult heartworms can live in a dog’s organs and arteries at one time. Treatment consists of injections that kill adult heartworms over several weeks. Since dead and dying heartworms can block the pulmonary arteries, heartworm treatment always poses a severe respiratory emergency risk. For this reason, a dog must be hospitalized for several hours after each injection and their exercise must be restricted for the treatment’s duration.

Cats are resistant heartworm hosts, and typically no more than three adult heartworms infiltrate their tissue. However, a cat’s body mounts an immune response that kills the heartworms, posing clot risks in the pulmonary arteries. Such a blockage can suddenly deplete an infected cat’s oxygen, and the cat dies. In addition, cats can develop a condition called heartworm-associated respiratory disease (HARD), which causes severe respiratory issues. No current heartworm disease treatment is available for cats, making prevention crucial. 

The best medicine: Heartworm prevention in pets

Pets’ heartworm prevention is light years ahead of treatment in terms of cost, ease, and effectiveness. Heartworm prevention options range from a monthly chewable tablet or topical application to a twice-yearly injection. Our veterinarian can recommend the most effective prevention for your pet based on your furry pal’s age, lifestyle, and overall health. 

You must administer your pet’s heartworm preventives on a strict schedule and at the correct dose. Prevention works by interrupting the heartworm life cycle and preventing the microfilariae from reaching adulthood. Adult heartworms are resistant to preventive medication, so the microfilariae must be prevented from reaching the adult worm stage. Monthly prevention works because the microfilariae need about 51 days to reach the adult stage. Therefore, when your pet receives heartworm disease prevention monthly and on schedule, your furry pal remains protected. Even one missed dose can allow adult heartworms to develop in your pet’s heart and lung tissue. In addition to regular preventives, you can help prevent your pet from contracting heartworm disease by doing the following: 

  • Keep your pet indoors when mosquitoes are most active — In southern and subtropical states, such as Alabama, evenings are peak times for mosquitos, so keep your pet inside during that time. 
  • Use pet-safe mosquito repellent — Protect your furry pal when they are outdoors by spraying them with a pet-safe mosquito repellent.
  • Schedule regular preventive veterinary exams — Our veterinarian will test your pet annually for heartworm infection, which can prevent long-term damage and the need for treatment. 

Our Town & Country Animal Hospital team knows how much you care about your pet, and we are passionate about protecting them from heartworm disease. Contact us with any questions or concerns about this serious problem.