Fleas, Ticks & Heartworms Are Bad Mews

Cat parents are finally getting the message to protect their cats against flas, ticks and heartworms. According to the American Pet Products Association, parasiticide sales for cats are up.

“It’s about time,” cheers veterinary parasitologist and Distinguished Professor Emeritus Dr. Michael Dryden, Kansas State University College of Veterinary Medicine. “The time is right, right now for cats.”

Led by millennials, cat parents are open to doing the right thing and,, veterinary professionals are talking more often about the importance of control for cats. With more cats hanging out in catios or taking a stroll in cat strollers or on a leash and harness, they are more prone to exposure to parasites. And, without protection,
consequences can be dire, and even impact human health.

Full-stop flies

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So, what’s the big deal about flea protection for cats? “Well, fleas are blood-sucking parasites,” Dr. Dryden says. Enlarge a video of a flea biting a cat — and nightmares are guaranteed to follow.

Gross as they are, here are the details: The flea injects saliva while sucking blood, and it’s antigenic (a substance that causes the body to make an immune response against that substance). That reaction commonly causes pruritus (itchy skin), which is often associated with hair loss. This reaction is known as the most common skin disease in cats in North America, called flea allergy dermatitis.

A single bite can cause a flea allergy — which is at best uncomfortable to cats
and may worsen to bacterial infection as the cat itch.

That’s the secret — appropriate veterinary suggested protection. “Protection shouldn’t come from over-the-counter products with fancy marketing,” Dr. Dryden says. Because a female flea can lay up to 50 eggs daily, a product that claims 90% effective isn’t in reality effective enough.

“You do need 99% effective or better to actually stop their reproduction,” he says. “And that is where the new modern isoxazoline transdermals that work systemically or new orals for cats are able to do and they are remarkably safe.”

In fact, he adds that it’s ironic that many concerned about safety turn to old-school dips and foggers, which may be less safe for cats or for people, or to products making claims like “all natural,” but just aren’t effective enough to fully protect your cat.

Except for high altitude and very dry locales — where flas are few and far between — Dr. Dryden suggests flea protection even for truly indoor cats because humans or even dogs who are protected can inadvertently deliver an interloper flea, and it’s off to the races. Do the math: 50 flea “babies” a day and in a matter of weeks those babies are having babies.

Truth about ticks

Dr. Katie Reif, parasitologist and assistant professor of Diagnostic Medicine and Pathobiology at Kansas State University College of Veterinary Medicine, says, “It’s a common misconception that cats somehow don’t get tick disease or groom ticks off before the tick can inject a pathogen.”

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While cats apparently don’t get Lyme disease from the black-legged tick (also known as the deer tick), they can get anaplasmosis, a bacterial disease. Signs may not be noticed by cat parents or cats may not be tested, as these cats generally don’t get all too sick — though they likely feel “yucky.” She says she has no doubt that anaplasmosis is underdiagnosed, and still not something you want your cat to have.

Cytauxzoonosis (also called bobcat fever) is another matter altogether, as even with successful treatment, odds may be at best 50/50 that the cat survives this severe disease caused by Lone star ticks. Dr. Reif also notes that cats who survive cytauxzoonosis may become a reservoir, allowing even more ticks to affect more cats.

Meanwhile — like many tick species — the black-legged tick, Lone star tick and American dog tick are all expanding their ranges in the United States. American Dog ticks are responsible for cats becoming significantly ill from tularemia, which is a bacterial disease.

Of course, it’s unlikely that an indoor-only cat (who truly never ever ventures outside) will be exposed to ticks, though it does happen. Still, keeping cats indoors-
only offers a great defense. For cats who even only occasionally may walk on a leash and harness and definitely those in lanais, porches or catios or live with a dog — tick prevention (using a product suggested by your veterinary professional) is a far better option than the risk of tick disease. “I’d love to see more cat parents protect their cats,” Dr. Reif adds.

Heartworms — not just for dogs

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Heartworm disease is spread by mosquitoes and has historically mostly been associated with dogs, but Dr. Dryden notes that it is likely often undiagnosed in cats.

“Heartworms prefer dogs, as cats are not their natural host, and therefore cats may respond with a violent immune response — sometimes to even a single worm,” Dr. Dryden says.

“Baby worms” or microfilariae larvae are passed into the cat while an infected mosquito takes a blood meal. Even immature worms may cause real damage in the form of a condition known as heartworm associated respiratory disease (HARD), which mimics feline asthma. And even if there is no apparent impact — there is likely a price the cat will pay for having to deal with heartworm.

Moreover, the medication used to treat heartworm infections in dogs cannot be used in cats, so prevention is the only way to protect cats from the effects of heartworm disease. Also, according to at least one study, feline heartworm is the second most common cause of sudden death in cats.

“Heartworm in cats is a totally preventable disease, which may cause death or disease like asthma and will likely always impact the cat, and there is no treatment,” Dr. Dryden says. “Of course, it should be a priority to protect against heartworm.”

Learn more about heartworm disease at, heartwormsociety.org. Learn more about fleas, ticks and other parasites at petsand parasites.org. And any product to protect against fleas, ticks or heartworm to be used on cats must be labeled for cats.

Preventing Cat Scratch Disease

Veterinary parasitologist and Distinguished Professor Emeritus Dr. Michael Dryden of Kansas State University College of Veterinary Medicine explains that flea can carry Bartonella henselae, the primary cause of Cat Scratch Disease. Carried at the base of the cat claw, a scratch to an immune-compromised person or a senior citizen can cause severe disease.

Dr. Dryden adds that, according to one study, about half of all cats in a study area in the South were positive for Bartonella henselae. He adds that numerous studies demonstrating that appropriate flea control can 100% prevent Bartonella henselae and therefore Cat Scratch Fever.

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