With so many diseases, infections, and parasites threatening your pet, keeping them all straight can be difficult. Fortunately, we are here to help, and to ensure your pet is adequately protected from as many preventable conditions as possible. Pet owners hear many misconceptions about heartworm disease and its risk to pets, so to set the record straight, we are busting 10 common myths about heartworm disease.
Myth #1: A heartworm-positive dog can infect my dog
Heartworms require a mosquito for transmission. A mosquito that bites an infected dog picks up microscopic larval worms with its blood meal, the worms develop in the mosquito, and then are transmitted when the mosquito bites another dog. If your dog lives with or near a heartworm-positive dog, mosquitoes may carry the infection to your dog, but she cannot be directly infected through contact with the heartworm-positive dog.
Myth #2: If dogs near my pet do not have heartworm disease, she will not get it
Heartworms prefer canine hosts, which include dogs, wolves, coyotes, and foxes. Your neighborhood dogs may be heartworm-free, but mosquitoes can pick up heartworms from local wildlife, or stray dogs. Most rural and suburban areas have a thriving wildlife population in woodland pockets, and stray dogs can serve as an infection reservoir for city pets.
Myth #3: If my pet has heartworms, I will see them in her feces
Although many worm types, such as roundworms and tiny hookworms, are shed in your pet’s feces, heartworms do not live in the gastrointestinal (GI) tract, and are not found in feces. Heartworms live in a pet’s heart and surrounding large blood vessels, where they cause significant inflammation, and interfere with normal blood flow. The only way to know if your pet has heartworm disease is through a blood test, which detects the presence of adult female worms.
Myth #4: My pet will act sick if she has heartworm disease
Since heartworms cause significant heart impairment, lung damage, and disease that progresses to death, you would expect that your pet would quickly let you know if she becomes infected. Unfortunately, pets with heartworm disease show few signs until infection is severe, and significant damage has occurred. The few larval worms deposited by a mosquito take approximately six months to mature. Once adult worms begin to reproduce, worms accumulate, and your dog may show vague clinical signs, such as lethargy, coughing, and vomiting, but, unfortunately, she may be infected for a year or longer before you see any signs.
Myth #5: I can stop giving my pet heartworm prevention during the winter
Although New York winters can be frigid, mosquitoes are hardy, and can emerge any time temperatures rise above 50 degrees. With the recent mild winters and unpredictable weather, year-round protection is safest, to ensure your pet isn’t bitten by a rogue January mosquito.
Myth #6: Skipping a dose or two of my pet’s heartworm preventive is not a big deal
Missing only one dose of heartworm protection leaves your pet exposed to infection and disease. Heartworm preventives work retroactively, killing larval heartworms that may have been transmitted by a mosquito bite. They are effective for approximately one month, so if your pet is bitten by an infected mosquito during the month she does not receive a prevention dose, larval worms may persist, instead of being killed. Once the worms reach a certain development point, the preventive medication is no longer effective, and they will continue developing into adult worms.
Myth #7: My indoor pet does not need heartworm prevention
All pets should receive heartworm prevention, whether they venture outside, or not. Mosquitoes certainly find their way inside—according to the American Heartworm Society, 25% of cats diagnosed with heartworm disease are indoor-only pets. Your indoor pet needs heartworm prevention, to protect her from mosquitoes that follow you through an open door, or squeeze through a crack in your home defense.
Myth #8: My pet does not need an annual heartworm test if she receives regular prevention
While assuming that prevention every month equals a negative heartworm status makes sense, testing your pet annually is critical. We want to ensure the medication is protecting your pet, and if you accidentally miss a dose, your dog spits it out, or she vomits it in a backyard corner without your knowledge, she can be left unprotected.
Myth #9: Cats can’t get heartworm disease
Although dogs are the preferred heartworm host, cats can still be affected, and can develop significant disease. The few worms transmitted by a mosquito bite cannot reproduce in a cat, but they can live for up to three years, and cause significant inflammation. Heartworm infection in cats causes heartworm-associated respiratory disease (HARD), named for the condition’s significant lung inflammation and asthma-like symptoms. The inflammation triggered by the worms’ presence can cause collapse, and sudden death, in affected cats.
Myth #10: If my pet gets heartworms, she can simply be treated
Heartworm disease treatment for dogs is available, but is lengthy, risky, and expensive. Treatment typically spans several months, with a medication to kill the adult worms intermittently injected deep into a dog’s back muscles. Between adulticide treatments, additional medications are administered to eliminate juvenile worms, decrease inflammation, and kill bacteria carried by the worms that contribute to inflammation. During treatment, activity is restricted, to reduce the risk of deadly pulmonary embolism, which can occur if dead worms lodge in a blood vessel.
Medication to kill adult heartworms is not available for cats, and treatment focuses on decreasing inflammation, until the worms die on their own. Since no curative treatment is available for cats, prevention is critical.
Hopefully, we have set the record straight, and you understand that heartworm disease is a threat to every pet. Call us at Homestead Animal Hospital, to schedule your pet’s heartworm test or Interceptor Plus refill.