Flea Control in Cats

Where did my cat get fleas?

The most common flea found on cats and dogs is the cat flea (Ctenocephalides felis), although any species of fleas, including fleas from rabbits, squirrels or other wildlife, can be found on cats.

The most important source of cat fleas is newly emerged adult fleas from flea pupae in your house or yard. Adult fleas live, feed and mate on our pets; the female flea lays eggs that fall off into the environment where they hatch into larvae. The larvae eat organic debris until they mature into pupae. The pupae are encased in a sticky cocoon, helping them to camouflage in the environment and making them difficult to eradicate. Adult fleas will not emerge from the pupae until they sense an animal nearby to feed on. Newly hatched adult fleas jump onto a host animal to complete their life cycle. Two days after eating a blood meal from the host, the female flea begins to lay eggs. Under ideal conditions, the flea can complete its entire life cycle in as little as two weeks; in adverse conditions, the fleas within the pupae remain dormant and can wait as much as a year to hatch, when conditions are more desirable.

Homes with carpets and central heating provide ideal conditions for the year-round development of fleas. The highest numbers of flea eggs, larvae and pupae will be found in areas of the house where pets spend the most time, such as their beds and furniture. Even though fleas may be in your house, you probably won't see them. The eggs are tiny white specks the size of dust particles, while the larvae, which are somewhat larger, with dark heads and lighter bodies, migrate deep down in carpets, furniture or cracks in floors away from the light.

What effect do fleas have on my cat?

Many cats live with fleas but show minimal signs. In pets who are allergic to fleas, even one or two bites can cause extreme itching, leading to self-trauma and skin infections. Since they feed on blood, fleas can cause anemia (low red blood cells) in heavy infestations, especially in young or debilitated cats. In addition, fleas can carry several diseases, including plague, and act as vectors (hosts) to spread one of the most common tapeworms of the dog and cat, Diplylidium caninum. In fact, due to the effective grooming behaviors of cats, in some cases, tapeworms are the only sign that a cat has been exposed to fleas.

How can I get rid of fleas on my cat?

This can be a challenging task and requires a three-pronged approach. Fleas need to be eliminated from your 1) cat, 2) from any other cats and dogs that you have, 3) from your home and yard. Once your cat’s fleas are under control, continued prevention is essential, since you cannot control some outside sources of fleas such as other people's pets, wild animals or other property outside yours.

What products are available to treat my cat?

Although many OTC flea shampoos, sprays, and powders will kill adult fleas on your cat at the time of application, they can have limited effectiveness because they only work for a few hours after application. Most have no residual effect, meaning your cat will be infected with new fleas from the environment by the next day. Monthly preventive products with excellent residual activity, such as Revolution and Frontline Gold, are available from your veterinarian. Some products contain adulticide ingredients (kills adult fleas) with residual activity, while others contain insect growth regulators(IGR's) that prevent the larval stages from maturing and in effect sterilize the fleas. Please consult with your veterinarian to choose the product that is best for your cat.

ALWAYS READ THE LABEL CAREFULLY – make sure the product is safe for cats, apply the product as instructed, and repeat at the intervals stated. Many dog products contain ingredients that are toxic to cats.

How can I treat my home environment?

In cases where fleas have invaded your home or yard, environmental treatment is crucial in controlling the population. This is because the adult fleas which are killed by our preventive medications only constitute about 5% of the population. The remaining life stages are hidden in your carpet, furniture, bedding, and yard (see flea life cycle section).

• A number of different products are available which will kill the adult and larval stages of fleas and stop the flea life cycle, such as:
• Adulticide sprays for use in the house (such as Knockout Spray)
• Sprays containing insect growth regulators (IGR's) for use in the house
• Insecticides applied by professional pest control companies

Sprays for use in the house should be used in places where the flea eggs, larvae and pupae are likely to be. It is recommended that you treat the entire household first and then concentrate on the hot spots - your cat's favorite napping spots - such as soft furniture, beds, and carpets. Once they hatch from the egg, flea larvae move away from the light and burrow deep into carpets and into other nooks and crannies where it is difficult to reach. Be sure to move cushions, furniture and beds to spray underneath them. Other places larvae are likely to live include baseboards and the cracks and crevices between floor seams or boards. You will need to throw away the vacuum bag to prevent eggs and larvae from developing inside the vacuum cleaner.

Flea eggs and pupal cases are extremely tough and resistant to the effects of insecticides. To remove these stages, as well as eliminate dead fleas, your pet's bedding should be washed in hot water or replaced. Regular and thorough vacuuming of your carpets, floors and soft furnishings can remove a large number of flea eggs, larvae, and pupae. Sprinkling carpet with diatomaceous earth or borax powder can help improve the mechanical destruction of flea larva by the vacuum. Vacuuming prior to the application of a spray to the house is recommended because the vibrations will encourage newly developed fleas to emerge from pupae, which will then be killed by the insecticide. *Note that some environmental treatment products contain pyrethrins or permethrins, which are toxic to cats. Cats should be isolated prior to treatment of the house with these products, and the products should be allowed to dry for several hours before reintroducing the cats.

Are insecticides safe for my cat and my family?

Insecticides for flea control should be safe both for pet dogs, cats and humans provided the manufacturer's instructions are carefully followed. One should be particularly careful to avoid combining insecticides with similar modes of action. Always seek your veterinarian's advice if you are unsure about this and always tell your veterinarian about any flea control products you may be using other than those that he has prescribed.

Products containing pyrethrins or permethrins can be toxic to cats when first applied – it is important to wait. Certain types of pets (e.g. birds, fish, amphibians, reptiles and invertebrates) may be particularly susceptible to some products. Do not use any flea control products in the room in which these pets are kept without first consulting your veterinarian for advice.

I have not seen any fleas on my cat. Why has my veterinarian recommended flea control?

Fleas are easy to find if a cat is heavily infested. If fleas are present in smaller numbers, it can be harder to see them. Fleas move fast! Try looking on the cat's stomach, around the tail base, and around the neck. Sometimes adult fleas cannot be found but "flea dirt" can be seen. This is fecal matter from the flea that contains partially digested blood, and it is a good indicator of the presence of fleas. Flea dirt is seen as small black specks or coiled structures; when placed on damp white tissue, it dissolves, leaving a reddish-brown stain. Flea dirt may be found in cat's bedding even when fleas cannot be found on the cat.

Many cats with fleas will groom excessively. Cats are very efficient at removing debris from their coat's using their tongues and may succeed in removing all evidence of flea infestation such as adult fleas and flea dirt. One of the most common causes of feline allergic skin disease is flea allergy dermatitis. To eliminate this possibility your veterinarian may advise rigorous flea control even though no fleas can be found. If the cat's skin problem improves with flea control then it suggests that flea allergy is involved.

Despite treating my cat for fleas he still has them. Is there a "super flea"?

There is no evidence of fleas developing resistant to insecticides, especially the newer once-a-month topical flea preventives that contain a sterilizing agent or IGR in addition to the adulticide. Apparent failure of treatment almost always results from improper application of the preventive, inadequate treatment of the home or exposure to other infested pets or environments. Consider treating storage sheds cars and any outdoor sleeping spots. Bear in mind that your cat may be going into other people's houses. Most of these problems can be overcome by using an effective product with residual activity on the cat in addition to treating your home.

It is important to remember that due to the tough nature of the flea pupae, it can take 2-3 months to completely eliminate fleas from your environment. During this time you may continue to see occasional adult fleas on your pet - THIS DOES NOT MEAN OUR TREATMENT IS NOT WORKING! Stick with the plan, and with time the population can be eradicated. You may also see adult fleas if your cat goes outdoors or visits environments which you can’t control, your preventive product should kill them quickly before they can establish a new infestation in your environment.