Where does my cat get fleas?
The most common flea found on cats and dogs is the cat flea (Ctenocephalides felis). Rarely rabbit fleas or hedgehog fleas are also found on cats.
The most important source of cat fleas is newly emerged adult fleas from pupae in your house or yard. Adult fleas live and feed on our pets but the female flea lays eggs, which fall off into the environment. Under favorable conditions, these eggs develop first into larvae and then into pupae. The pupae contain adult fleas that lie in wait for a suitable animal host. Modern carpeted centrally-heated homes 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 too small to see without magnification and the larvae, which are just visible, 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. However, the following problems can occur:
- Some cats develop an allergy to flea bites, especially if they are repeatedly bitten. If these cats are bitten by fleas they groom or scratch excessively and develop skin disease.
- Adult fleas live on animals and feed on blood. In kittens and debilitated animals this may cause anemia.
- The flea acts as the intermediate host for the tapeworm (Dipylidium caninum). Tapeworm eggs, which are shed within tapeworm segments in cat feces, are eaten by flea larvae that develop into infected fleas. Cats become infested by swallowing infected fleas during grooming. Any cat with fleas is likely also to have a tapeworm infestation.
How can I get rid of fleas on my cat?
This can be a demanding task and requires a three-pronged approach. Fleas need to be eliminated from your cat, from any other cats and dogs that you have, from your home and from your yard. Even this rigorous approach may not give 100% control as there are other sources of fleas that are beyond your control such as other people's pets, wild animals and infested environments which your cat may come into contact with outside your house.
When it comes to environmental control, we must first understand the flea life cycle.
There are four stages in the life cycle of the flea:
- Flea eggs are whitish and about 0.5 millimeter (mm) (1/32") in length. They are unlikely to be seen without a magnifying glass. Eggs are laid by the adult flea after taking a blood meal. The eggs are initially laid on the dog's skin but fall off into the environment to continue their lifecycle. Flea eggs constitute approximately 50% of the total flea population. Eggs may hatch in as little as 14 to 28 days, depending on environmental conditions. High humidity and temperature favor rapid hatching
- Flea larvae are about 2-5 mm (1/8" to 1/4") in length. They feed on organic debris found in their environment and on adult flea feces. They dislike bright light and move deep into carpet fibers or under furniture, organic debris, grass, branches, leaves and soil. Flea larvae prefer warm, dark and moist areas. Outdoor larval development occurs only in shaded; moist areas where flea infested pets spend a significant amount of time. Our climate-controlled homes offer an ideal environment for the flea larvae to thrive.
- The flea pupae produce a protective silk-like cocoon which is sticky. It quickly becomes coated with grime and debris, which acts as a useful camouflage. With warmth and humidity, pupae become adult fleas in 5-10 days. The adults do not emerge from the cocoon unless stimulated by physical pressure, carbon dioxide or heat. This is important since once fleas emerge from the cocoon they can only exist for a few days unless they are able to feed. Pre-emergent adult fleas can survive within the cocoon for up to 9 months. During this time they are resistant to insecticides applied to the environment. This is important to remember because adult fleas may emerge into the environment a considerable time after you apply insecticides in your home.
- Once it emerges, the flea adult, unlike the larvae, is attracted to light and heads to the surface in order to encounter a passing host to feed upon. Two days after the first blood meal, female fleas begin egg production. In normal circumstances the adult female will live up to three weeks, laying approximately 40 eggs per day. The entire life cycle, from egg to adult flea can be completed in 14-28 days depending on environmental conditions.
What products are available to treat my cat?
Insecticides applied to cats are designed to kill adult fleas. Many products have limited effectiveness because they only work for a few hours after application. This is particularly true of flea shampoos and powders; they kill fleas present on your cat at the time of application but have little residual effect so the day after use the cat may again have fleas. There are new products with excellent residual activity that are available from your veterinarian. In addition to adulticides, there are several products on the market that contain insect growth regulators, which effectively sterilize the fleas and prevent flea infestations.
ALWAYS READ THE LABEL CAREFULLY - apply the product as instructed and repeat at the intervals stated.
My cat hates being sprayed. What can I do?
Many cats strongly dislike being sprayed. Consult your veterinarian, as there are several alternatives available. Flea collars are very convenient but they don't work well or provide sufficient control for a flea allergic cat and are not generally recommended. Additionally, some flea collars, especially ones with a strong pesticide smell, may be harmful to some cats. Some cats will develop a skin reaction to collars. There are flea foams available that you brush into your cat's coat. Topical flea preventives are highly recommended because of their efficacy and ease of application.
How can I treat my home environment?
A number of different products are available which will kill the stages of the flea life cycle present in your home such as:
- Insecticide sprays for use in the house
- Sprays containing insect growth regulators (IGRs) for use in the house
- Insecticides applied by professional pest control operatives in your house
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 dozing 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 treat. Be sure to move cushions, furniture and beds to spray underneath. Other places larvae are likely to live include baseboards and the cracks in wooden floors.
Your pet's bedding should be regularly 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 that are present in your home. You will need to throw away the vacuum bag to prevent eggs and larvae from developing inside the vacuum cleaner. 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 be killed by the insecticide.
How do I choose which products to use?
A flea control program needs to be individually tailored based on the lifestyle of your cat and other pets, and your family situation. Your veterinarian is the best person to advise you about safe and effective flea control products.
Are insecticides safe for my cat and my family?
Insecticides for flea control should be safe both for pets 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 which he has prescribed.
Certain types of pets (e.g. 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 advised 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 and 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 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, they dissolve, leaving a reddish brown stain. Flea dirt may be found in cat's bedding even when fleas cannot be found on the cat.
In cats that develop an allergy to fleas one of the symptoms is excessive grooming. 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 investigate 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.
I noticed my cat had fleas after his return from boarding. Did he get fleas there?
Not necessarily. Newly hatched adult fleas can survive for up to 140 days within the pupa. When you and your pets are absent from home for extended periods of time these adult fleas remain in the pupae because no host is available. As soon as you or your pet returns home, these fleas will emerge in large numbers and jump onto cats, dogs and even people in the search for a blood meal.
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. 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 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 on the cat to kill adult fleas in addition to treating your home.