Fleas
Fleas are small biting insects that cause itching and can trigger allergies, anaemia in young animals and tapeworm infection. Most of a flea infestation lives in the home as eggs, larvae and pupae, not on the pet. All pets in the household and the home itself need treating.
Go to a vet now if
- A kitten or puppy with heavy fleas that is weak or has pale gums.
- A cat showing twitching, trembling or fits after a flea product was used.
- An elderly or sick pet with heavy fleas that seems weak or tired.
What you might notice
- Scratching, nibbling or biting at the back and base of the tail.
- Black specks of flea dirt in the coat.
- Red bites, scabs or sore skin.
- Hair loss or a rough coat.
- Rice-grain-like tapeworm segments near the bottom.
Common causes
- Contact with other animals or their environment.
- Flea pupae waking up in the home months after an earlier infestation.
- Gaps in regular flea prevention.
- Untreated pets in the same household.
What you can do at home
- Treat all dogs, cats and rabbits in the home at the same time with vet-recommended products.
- Vacuum regularly, especially around beds and under furniture.
- Wash pet bedding at 60°C or hotter.
- Treat for tapeworm after a flea infestation, as advised by your vet.
Book a vet in the next day or two if
- Fleas keep coming back despite treatment.
- Sore, broken or infected skin.
- Severe itching or hair loss from flea allergy.
Don't
- Never use a dog flea product on a cat; products containing permethrin can kill cats.
- Do not use household flea sprays containing permethrin around cats, fish or birds.
- Do not treat only the pet that is scratching.
Prevention
- Use regular flea prevention that suits each pet's species and weight.
- Ask your vet which product to use; many shop collars and shampoos work poorly.
- Check the coat regularly with a flea comb.
This guide gives general information about common health problems in dogs and cats. It is not a diagnosis and it does not replace an examination by a veterinarian. Every animal is different, and signs that look mild can sometimes hide a serious problem, especially in cats, which often hide illness and pain. If you are worried about your pet, or if your pet shows any of the warning signs listed here, contact your vet or the nearest emergency veterinary clinic straight away. Never give your pet human medicines or any medicine not prescribed for that animal by a vet.
Sources
Sources
Checked against these sources in October 2026.