Fleas are small, 6 legged, blood-sucking parasitic insects that feed on warm-blooded animals and are the most commonly encountered external parasites of pets. There are more than 2,200 species of fleas recognized worldwide, but the cat and dog flea are the flea species most commonly encountered in Ireland and the UK. All fleas are wingless, so their main mode of travel is jumping. They can jump more than 100 times their own length facilitated by their relatively long hind legs!
The number of fleas on your pet represents approximately 5% of the total population, the rest are scattered as eggs, larvae and pupae around your house - in your carpets, bedding, under furniture and between floorboards. When a flea jumps onto your pet, it will start feeding within 5 minutes and may suck blood for up to 2½ hours. Female fleas can consume up to 15 times their own body weight in blood.
A single flea can live on your dog or cat for almost 2 months! Flea infestations can rapidly get out of control. That’s because fleas lay eggs in such large numbers. At a rate of 40 to 50 per day for around 50 days, a single female can produce 2,000 eggs! Within as little as 2 days, flea larvae will hatch and hide in dark places on the ground, in carpets or upholstery. After about a week of feeding on adult flea droppings, crumbs, flakes of skin, etc., the larvae spin cocoons to become pupae. The pupae can remain in this stage for very long periods of time. The cycle continues when, as soon as a week or so later, the pupae develop into adult fleas and emerge from their cocoons when they sense that a dog or cat, or other animal host, is near. The cycle – which can take as little as 12 days or as long as 180 days – can then begin again.
Flea bites may go unnoticed on some pets, cause slight irritation in others and produce extensive itching, red lesions, hair loss and even ulcers in those animals with flea allergy dermatitis (FAD), which is the result of extreme sensitivity to flea saliva. Severe flea infestations can cause anaemia, especially in puppies and kittens.
Fleas have been shown to spread a number of diseases, some of which can be a serious health risk. Please check out our disease risks page to know more about the hazards associated with infestations of fleas or ticks.
Various products are available for controlling fleas. Your veterinary practitioner is best placed to advise you on the product of choice for your pet. For further information on the product for fleas, marketed by MSD Animal Health, please click here.