The “Eeewww” Factor: Fleas, Ticks and Heartworms
While most cat guardians know that parasites such as fleas, ticks and heartworms are hazards for cats with outdoors lifestyles, it’s also possible for indoors-only cats to suffer from some of these pests. Familiarizing yourself with the life cycles of these parasites, the clinical signs that an affected cat may have, preventive measures and safe and effective treatments will help you keep your kitties healthy and happy.
Fleas are the most common external cat parasite. Because they suck the blood of their hosts, they can cause life-threatening anemia in very young kittens or older, debilitated cats. Fleas tend to live on areas of the cat’s body that are difficult to reach and groom, so the back of the neck and the rump area typically are where you may find the adults or brown specks of flea “dirt” (which is actually flea feces). Taking a flea comb and rubbing the suspected flea dirt between the edges of a wet paper towel can help separate “just dirt” from flea debris. Flea debris will leave a rust-colored stain on the towel, due to the presence of digested blood.
The majority of the flea life cycle actually takes place off the cat. The kitty is used for a quick blood meal, but flea eggs, larvae and pupae are found off the cat, in and around the home. Flea larvae spin tiny cocoons (often in carpet fibers) and emerge as pupae. If you’ve ever wondered why it is so difficult to get rid of fleas, know that pupae are resistant to freezing, drying and insecticides. They can remain dormant for months, and are stimulated to emerge as adult fleas by vibrations (turning on the vacuum cleaner, for example), increased levels of carbon dioxide and warmth. Many times, a family will come home from vacation and within hours, will be dealing with flea bites. That’s because the increased level of carbon dioxide (talking, breathing) has caused the pupae in the home to emerge as adult fleas.
New adult fleas actually have a very short lifespan on healthy, adult hosts and if the cat is able to groom his or herself, most fleas do not survive for more than 72 hours on a kitty. In the right environment, however, the flea life cycle can be completed in as little as 16 days.
Some cats are incredibly sensitive to flea saliva and develop “flea bite dermatitis.” These poor kitties typically have patches of missing fur (most commonly at the rump and caudal thighs), intense itching (pruritus) and open wounds from self-trauma. Antibiotics and/or a short course of steroids need to be used for relief of these clinical signs.
Fleas also can transmit tapeworms (Dipylidium caninum) and another blood parasite, Mycoplasma hemofelis. Tapeworm segments (egg packets) typically look like small white rice granules and are found on the cat’s feces or around the kitty’s anus. Mycoplasma hemofelis infection often results in a life-threatening hemolytic anemia that can be accompanied by fever and lethargy. Cats who are clinically ill with M. hemofelis infections may require blood transfusions and typically receive antibiotics (doxycycline) and glucocorticoids during their crisis and recovery periods.
Clients often ask about safe, “natural” flea protection, but the truth is that there is no such proven product. The over-the-counter flea control products are to be avoided, as they can cause severe illness and even death in cats. Permethrin products, which can be found in various OTC flea control medications, are especially dangerous and can be lethal to cats. As always, the safest approach is to use a veterinarian-approved product and not try to save money by purchasing medications found in a grocery store or superstore. Never use flea products formulated for dogs on cats or kittens. If a cat or kitten is exposed to such products, call your local veterinarian or emergency clinic immediately.
Flea shampoos have little lasting effect and work to primarily remove the fleas from the cat. However, cats can experience toxicities if multiple products (flea shampoos, spot-ons, sprays, etc.) are used concurrently. Unless specifically recommended by your kitty’s veterinarian, never “layer on” multiple flea products.
Fleas can enter any home on the clothes of family members, on the family dog, through open windows and screens and can linger for days in the common areas (foyers and hallways) of apartment buildings and condominiums. Depending on where you live, the presence of dogs and other factors, your kitty’s veterinarian may recommend a flea control product for your indoors-only kitty.
In the past, flea control depended upon environmental sprays for management of flea infestations. Today’s flea control products work much better and longer than the older ones and work to break the life cycle of the flea at its various stages. Most veterinarians offer several such products, depending upon client preference for using spot-ons or tablets in their kitties and whether other parasites (such as roundworms, ear mites, ticks and heartworms) must be prevented as well.
Ticks are generally less of a problem in cats than fleas because cats are fastidious groomers who often remove the tick quickly. Some of the available flea control products work to prevent ticks as well. Ticks can spread a protozoan, Cytauxzoon felis, through their bites. This disease is almost uniformly fatal, with affected cats showing lethargy, fever and jaundice. Clinical signs are typically seen 12-15 days after the tick bite. Cytauxzoonosis can be found in some areas of the Midwest, southern States and along the Atlantic Coast.
Heartworms (Dirofilaria immitis) can cause a wide range of clinical signs and symptoms, including asthmatic-like coughing, difficulty breathing (dyspnea), vomiting and even sudden death in cats. The cat is an atypical host for this parasite, which is spread through the bite of an infected mosquito. Blood tests are available to see whether a cat has been exposed to mosquitos carrying heartworms (antibody testing) and whether the cat is currently infected (antigen testing).
