How to treat your pet for fleas

Most dogs and cats will pick up fleas at some point. Fleas make pets itchy and uncomfortable, can cause skin problems, and can quickly spread through a home. Treating them properly means treating your pet, every other pet you have and your home.

Safety first: use the right product for each pet

Never use a dog flea treatment on a cat. Some contain permethrin, which can be fatal to cats. Always use a product made for the species and weight of your pet.

If your cat has been treated with a dog product by mistake, or has been in close contact with a dog that has just been treated, contact your vet straight away. Also follow the manufacturer's instructions about keeping treated dogs apart from cats.

How do pets get fleas?

Pets pick up fleas from other animals that have them, and from places where flea eggs and larvae are living, such as gardens, other homes and bedding. Fleas have powerful legs and can jump onto a passing animal.

Life cycle of a flea

Understanding the life cycle explains why one treatment is rarely enough.

• Adult fleas live on your pet, feed on its blood and lay eggs.
• Eggs fall off your pet into carpets, bedding, household furnishings and gaps between floorboards.
• Larvae hatch and feed on flea dirt (adult flea droppings) and other debris, then spin a cocoon.
• Pupae develop inside the cocoon and wait for the right conditions, such as warmth or movement, before hatching into adults.

In a warm home the flea life cycle can be completed in a few weeks, and pupae can stay dormant for months. That is why new fleas can keep appearing for a while after you start treatment, and why fleas are a year-round problem in heated homes.

Signs your pet has fleas

• Scratching, chewing or licking more than usual
• Fleas moving in the coat, especially around the neck and the base of the tail
• Flea dirt: small dark specks in the coat that turn reddish-brown on damp white paper
• Red, irritated skin or hair loss

Some pets show no signs at all. Itchy skin can also have other causes, such as allergies or mites, so see your vet if you aren't sure.

Can fleas harm your pet?

Yes. Some pets develop flea allergy dermatitis (FAD), an allergic reaction to flea bites that makes the skin very itchy and sore. A heavy flea burden can cause anaemia, which is especially dangerous for young, small or elderly animals. Pets can also swallow fleas while grooming and pick up tapeworm.

If your pet seems weak, has pale gums or is a very young puppy or kitten with fleas, contact your vet promptly.

What to do if your pet has fleas

1. Speak to your vet. They can confirm the problem, check for skin damage and recommend a treatment. Vets can also prescribe products that aren't sold in shops.
2. Treat every pet in the home, using a product made for each animal's species and weight.
3. Treat your home. Vacuum carpets, furniture and pet beds thoroughly, empty the vacuum outside, and wash pet bedding on a hot wash. Your vet can advise on household flea sprays and how to use them safely around pets.
4. Keep going. Because pupae can hatch for weeks, keep up treatment as directed even after you stop seeing fleas.

Flea treatments

Flea products come as spot-ons, tablets, collars and sprays. Some also protect against other parasites, such as worms or ticks. How well they work varies, and products bought in shops or online aren't always as effective as those your vet can prescribe.

Treating all pets in the home regularly, at the interval on the product, is the best way to prevent fleas coming back. Ask your vet which product is right for each pet, and always follow the manufacturer's instructions.