Heartworm disease, which can be fatal for dogs and cats, is a serious concern for pet owners. In honor of National Heartworm Awareness Month, our Livingston Veterinary Hospital team is shining a light on 10 important facts you need to know about heartworm disease in your pet. 

#1: Mosquitoes transmit heartworm disease to pets

Unlike many other diseases your pet can contract, heartworm disease is not spread through direct pet-to-pet contact. Instead, an infected mosquito that transfers heartworm larvae has to bite your pet. So, you may know of a neighborhood pet who has heartworm disease, but they cannot directly infect your pet, although they can act as a reservoir for a potential infection.

#2: All pets are susceptible to heartworm disease

Many people think of heartworm disease as a canine-only disease, but any mammal, including cats, horses, and people, can be affected, although heartworms prefer dogs and wild canines as their host. Since cats are not the ideal heartworm host, they can suffer much earlier in the disease process. They can also suffer more severely from a heartworm infection, and one single adult heartworm can cause sudden death.

#3: The heartworm life cycle is fairly long

Unlike some other parasites, the heartworm has a fairly long life cycle. Whereas fleas can complete their life cycle in as little as 21 days, heartworms require months to reach adulthood and begin reproducing. After an infected mosquito bites your pet and transmits heartworm larvae, the larvae take six to seven months to reach adulthood and begin multiplying in your pet’s bloodstream.

#4: Heartworm disease can take months to cause visible signs in dogs

Since heartworms take so long to mature and reproduce in your pet, you may not notice any signs for months or sometimes years. The first sign is usually a mild cough, followed by fatigue after moderate activity. Next, the cough worsens and becomes dry and hacking and more frequent, and your pet will be increasingly exercise intolerant. If your pet develops heart failure, their abdomen may swell with fluid accumulation. The single best way to know whether your pet has contracted heartworms is through annual testing during their wellness visit. 

#5: Heartworm disease appears differently in cats and dogs

While dogs generally don’t display heartworm disease signs until later in the disease process, cats are much more sensitive. They can develop asthma-like signs, such as coughing, wheezing, and difficulty breathing, as the immature larvae wriggle through their bloodstream. They may also have vomiting or diarrhea, difficulty walking normally, or seizures, as their immune system fights off the foreign invaders. In some cases, a heartworm infection can cause sudden collapse or death.

#6: Early heartworm disease in pets can be difficult to detect

Although your pet may have been bitten by an infected mosquito three months ago and contracted heartworms, they will receive a negative test result. For an accurate test, your pet must have received the infective bite six months prior to the test. Typical heartworm tests can detect only the adult female heartworms, which can make early detection difficult. For example, if your pet missed a heartworm prevention dose in January and was tested for heartworm disease in April, they would receive a negative test result, because any heartworms in their bloodstream would be too immature for detection.

#7: Heartworm disease is difficult to treat in dogs

If your dog develops a heartworm infection, their treatment can last for months. They will need injections deep into their lumbar muscles that can be uncomfortable, as well as severe exercise restriction to prevent any complications from the heartworms dying and breaking up, and causing a blockage. Some dogs may require additional heartworm treatment after the initial phase.

#8: No heartworm treatment exists for cats

While heartworm can be treated in dogs, no federally approved option is available for cats. Instead, infected cats are provided with nursing care and disease management to give them the best possible quality of life.

#9: Pets should be tested annually for heartworm disease

Since heartworm testing can be challenging in the early infection stage, all pets should be tested annually for heartworm disease. This ensures that any larvae that may have slipped through and had a chance to develop to adulthood can be detected through testing, and that the disease is prevented from progressing too long undiagnosed.

#10: Heartworm disease in pets is easy to prevent

Heartworm disease in pets is much easier to prevent than to treat, and also much more economical. Treatment can cost thousands of dollars, while a year’s worth of heartworm preventive costs a fraction of that price. And, if you’re unsure about getting a pill into your pet, you can choose alternatives. We offer topical and oral heartworm preventives, and can help you choose the best fit for your furry pal’s needs, and ensure they’re protected from deadly parasitic diseases. 

As Livingston warms up after the winter months, heartworm prevention is much more critical for pets. Ensure your pet is healthy and heartworm-free by contacting our Livingston Veterinary Hospital team for an appointment. You can stock up on heartworm prevention while you’re here.