Ticks and Fleas on Cats Q&A: Control, Treatment, and Illness Concerns

WebMD veterinary expert answers common questions pet owners have about fleas and ticks on their cats.

By Sandy Eckstein
WebMD Pet Health Feature

Reviewed by Mark J. Stickney, DVM

With just a few exceptions in the United States, fleas and ticks are a common problem for us, and our cats. So we went to internationally known flea and tick expert Michael Dryden to find out how to fight the flea and eliminate the tick. Dryden has a doctorate in veterinary parasitology, is a founding member of the Companion Animal Parasite Council, and has conducted research on almost every major flea and tick product on the market.

Q: How can I tell if my cat has fleas or ticks?

A: Run your hand across them, part the fur, and look at them. Generally, on cats, look around the ears and the eyes for ticks. As far as fleas go, the easiest thing to do is roll it over and look at its belly. Look for fleas or flea dirt, which is basically the dried blood the fleas are defecating.

Q: Can my cat get sick from fleas and ticks?

A: Probably the most common problem is, when these fleas are feeding, they're injecting saliva into the skin. These salivary proteins are often allergenic and animals end up with allergy. The most common skin disease of dogs and cats is what's called flea allergy dermatitis, where they bite and scratch and lose their hair.

If you have a lot of fleas, since they're blood-sucking insects, especially if you have kittens, pets can become anemic and even die with heavy infestations. Fleas also commonly transmit tapeworms to our pets, at least one species.

Now ticks are different in cats than in dogs. There are some diseases that dogs get that cats don't. For instance, cats don't get Lyme disease. They get those ticks, they just don't get the disease. But they can get anaplasmosis; that's one that's not uncommon in cats. Cats can get tularemia. I believe they can get Rocky Mountain spotted fever. And they get cytauxzoonosis, which is the lethal one. It's a blood parasite of cats that occurs from about central Kansas almost in a straight line down to about Jacksonville, Fla. In some areas it's fairly rare, in others it's very prevalent. There is no effective treatment.

Q: Are fleas and ticks worse in some areas? Where?

A: Ticks and fleas can be worse from one area to another and can vary seasonally and from year to year. There's one particular flea species that we find on dogs and cats in North America that predominates. If you look it up it's called Ctenocephalides felis, or the cat flea, because its species name is felis. For that flea, the primary determining factor of populations is humidity. So why are their more fleas in Tampa, Fla., than in Kansas City? Why are there more fleas in Kansas City then Denver? Humidity. Once you get into the Rocky Mountain states, for example, or even the Western areas of the plains states, fleas on dogs and cats are not that much of a problem because it's just too dry. The Gulf Coast region of North America and the Southeast region are the flea capital. As you move inland, however, depending on the rainfall in a given year, it can be OK or get very horrid at times.

Ticks have different biologies and behaviors, of course. And there are different areas that have more tick problems than others. There are very few places in North America you can't encounter ticks today, because there are so many different ticks. But there definitely are areas that are worse than others.

Q: Can cats get heartworms?

A: Sure can. Absolutely. And it can be deadly in cats. Dogs get heartworm far more often than cats do. But when cats do get heartworm, it can definitely be lethal. I honestly believe that heartworm in cats is more lethal than heartworm in dogs, to that individual. There is no effective heartworm treatment for cats. All we can do for cats is try to treat the symptoms, manage the disease, until the worms die off. There are preventatives for cats, just like for dogs. If you put the cat on preventatives, it will keep them from getting heartworm, and if you use it when they have heartworms, it will keep them from getting more while you wait for the worms they have to die off. Some of these worms can live up to four years in a cat.

Q: Can I stop using preventatives in winter months, when all the fleas, ticks, and mosquitoes are dead?

A: No. I believe in most parts of the United States it should be year round. There are a few, limited exceptions, so there's no broad, sweeping statement you can make. Let's face it. I'm not putting a dog or cat on flea or tick treatment in Cheyenne, Wyo. It makes no sense. But in Atlanta, absolutely. You have to look at individual climatic conditions for individual areas and make that decision.

Q: An environmental group has sued several pet stores and manufacturers claiming that flea collars have high concentrations of chemicals in them that are dangerous to pets and people. Are these over-the-counter flea collars safe?

A: I'm not a toxicologist and I try to steer clear of all that. But I will say that I believe the best way to manage fleas and ticks is go to your veterinarian and find out what products he recommends for your area. The issue we have with many of the over-the-counter products is that many are what we call pyrethroids, or synthetic pyrethrins. We know that is a class of insecticides that fleas are commonly resistant to, so one of the reasons over-the-counter formulations don't work very well is that fleas are resistant to them. What that leads to is people tend to over apply them because they didn't work that well and then you tend to have problems

Q: There are also reports that the EPA is looking into an increase in adverse reactions from topically applied flea control products, the ones we usually put on our cats between their shoulder blades. So are these unsafe?

A: I generally believe, based on my experience and our field studies, that the products we get from our veterinarians are generally very safe and generally do a very, very good job. But you've got to understand that millions of doses are used each year. With that many doses, things happen. Do rare idiosyncratic reactions occur? Absolutely. We know they do. But generally with a veterinary recommended or prescribed flea or tick product, if they are used according to label directions, they are extremely safe in my experience. I'm a veterinarian and a dog and cat lover and I would not hesitate to put them on my pets.

Q: Can I use my dog's flea and tick products on my cat?

A: There are some products that can be placed on both dogs and cats. There are some products that you cannot put on cats because they can be very harmful. It could make your cat ill or even kill your cat. Cats are far more sensitive to some of these products than dogs are, so you need to be very careful that you're using the correct product. And the whole dose is based upon weight, so you don't want to put a dose for a great Dane on a cat. And sadly, that happens. People do that. And you end up with a sick or dead animal.

Q: Are there natural ways I can control fleas and ticks if I don't want to use chemicals?

A: There really aren't from a natural standpoint. Over the years we've spent some time looking into the more natural or holistic approaches and as yet I've not found any that's actually effective. The garlic, the brewer's yeast, all the research shows none of that stuff works. If it did, I'd be using it. The ultrasonic devices? The data shows they don't work.

And just because something is “natural” or “organic”, that doesn't mean it's safe. Most of the poisons in the world are actually organic poisons. Some of these citric extracts people used to use can be fairly toxic to cats. The cats' livers just can't handle them. With cats I'd be far more cautious just because cats are far more sensitive to some of these compounds.

Q: How can I control fleas and ticks in my home and yard?

A: Cut the tall grass, trim back the bushes and shrubs, then rake up all the leaf litter under the bushes. Leave it just bare ground. Nothing is worse on these arachnid life stages than dryness.

There are some lawn and garden insecticides that are approved by the EPA to be applied under shrubs, under bushes, in crawl spaces, along fence lines, to control fleas and ticks outside. The big issue I see is people tend to go out and start spraying their grass. That's not effective and it's certainly not good for the environment. Fleas and ticks are really sunlight and humidity sensitive. Most situations where we find them are under shrubs, under bushes, under porches, in shaded, protected habitats. So we should only be applying those compounds in a limited fashion under those locations. Then we're going to let it dry on the foliage for three to four hours before we allow our pets and our children back out there.

Q: How can I control fleas in my home?

A: If you have carpet, vacuum regularly with that rotary brush or beater bar. It's highly effective at reducing flea populations in homes. Wash your pet's bedding weekly to break the life cycle. Steam cleaning carpets can reduce the problem as well. If you have hardwood floors, damp mop with detergent on a weekly basis.