Fleas are one of the most common external parasites affecting dogs. The Big Flea Project, a UK study conducted in 2018, found that 14.4% of dogs examined were infested with fleas. Fleas can affect dogs of all ages. Heavy infestations can be dangerous for puppies and dogs that are older or unwell.
Fleas are easier to control when caught early; established infestations can take time to resolve. This is because flea eggs, larvae and pupae can remain in the home and continue to develop after adult fleas have been killed. Regular use of an appropriate flea prevention product, alongside treating the home when necessary, can help prevent and control infestations.
What are fleas in dogs?
Fleas are small, dark brown, wingless insects that feed on the blood of dogs and other animals.
Adult fleas live on their host, and their eggs, larvae and pupae are usually found in the surrounding environment, such as carpets, bedding and furniture.
How do dogs get fleas?
Dogs can pick up fleas from other animals, including cats and wildlife, or from the environment. Fleas can be found in gardens, parks, carpets, furniture and pet bedding. People can also bring fleas into the home on their clothing and shoes.
Adult fleas survive by feeding on blood. Heavy infestations can cause significant blood loss and anaemia, especially in puppies and dogs that are older or unwell.
Fleas can carry tapeworm larvae. Dogs can become infected with tapeworms if they accidentally swallow an infected flea while grooming. Find out more about worms in dogs.
Fleas are more common during the warmer months but can be present all year round, particularly in centrally heated homes.
Fleas have four life stages: egg, larva, pupa and adult. Under favourable conditions, the lifecycle can be completed in as little as 12–14 days. This allows infestations to build up quickly.
Adult fleas live mainly on animals. Eggs, larvae and pupae are found in the environment, including carpets, cracks, furniture and pet bedding. Flea pupae can remain dormant in their protective cocoons for several months, sometimes up to a year, before emerging when conditions are suitable.
Some dogs develop an allergy to flea saliva. In this case, even a single flea bite can trigger an itchy skin reaction. This is called Flea Allergy Dermatitis.
Flea infestations can be difficult to get rid of. Treating your dog, other pets and the home can help control an infestation and reduce the risk of it returning.
Speak to one of our online vets for more information.
Symptoms of fleas in dogs
Some dogs may have fleas without showing any obvious signs. Others may develop symptoms such as:
Itching, scratching, biting or licking their skin more than usual
Hair loss, especially around the lower back, tail base and hindquarters
Red, irritated skin, small raised bumps, scabs or sores (usually in dogs with flea allergy dermatitis)
Black specks in your dog's coat or bedding, known as flea dirt. These are flea droppings and can turn reddish-brown when damp.
Heavy flea infestations can cause blood loss and anaemia. This is more common in puppies and dogs that are older or unwell.
Contact your vet as soon as possible if your dog has pale gums, weakness or unusual tiredness, as these can be signs of anaemia and need veterinary assessment.
Are some dogs more at risk of fleas than others?
Dogs of any age, breed or sex can get fleas. However, some factors can increase their exposure or make fleas harder to spot.
Coat type: Fleas may be more difficult to spot in dogs with long, thick or dark coats.
Contact with other animals: Dogs that regularly mix with other animals, including cats and wildlife, may have more opportunities to pick up fleas.
Environment: Dogs that spend time in places where other animals have been, such as gardens, parks or shared bedding areas, may be exposed to fleas.
Other household pets: If one pet has fleas, other dogs and cats in the household are also at risk. All pets should be included in a flea treatment plan, where safe to do so, to help prevent reinfestation.
Is my family at risk of catching fleas?
Cat and dog fleas can bite humans, but they don't usually live or reproduce on human skin.
Flea bites often appear as small, red, itchy spots, commonly around the ankles and lower legs. They may appear in clusters or lines.
Scratching flea bites can irritate the skin and sometimes lead to secondary infection.
If you are concerned about flea bites, speak to a pharmacist or doctor for advice.
How are fleas diagnosed in dogs?
Diagnosing fleas in dogs is usually straightforward. You may be able to identify them at home, but a vet can help if you're unsure.
Fleas are usually diagnosed by finding live adult fleas or flea dirt (flea droppings) in your dog's coat.
Check areas such as the lower back, base of the tail, tummy and inner thighs. Adult fleas move quickly, so they can be difficult to spot.
A simple paper test can help identify flea dirt. Comb your dog using a fine-toothed flea comb over a piece of damp white kitchen roll or tissue. Flea dirt looks like small black specks. If you add a few drops of water, it will leave reddish-brown marks.
Fleas may also be suspected based on your dog's symptoms. Itching, scratching, and a pattern of hair loss or skin irritation around the lower back and tail can indicate a flea infestation.
Not finding fleas doesn't necessarily rule out an infestation, as dogs may groom them away and small numbers can be difficult to detect.
There are many other causes of itching in dogs. If your dog is showing these symptoms but you can't find any signs of fleas, speak to a vet for more information. Our Joii Vets are available 24 hours a day.
What’s the treatment for fleas in dogs?
Treatment of fleas involves killing the adult fleas on your dog and controlling their other stages in the environment.
Infestations can take time to resolve because immature fleas may continue to develop and emerge from the home after treatment begins.
Treat all pets in the household with a suitable flea product recommended by your vet. Products must be appropriate for each animal’s species, age and weight.
Choose the right product: Flea treatments are available as spot-ons, tablets and collars. Some are prescription-only, but there are some that can be bought without a prescription. Ask your vet which product to use.
Follow the instructions: Use the correct dose for your dog’s weight and repeat treatment at the interval stated on the product label or advised by your vet. Restrictions on bathing, grooming and swimming vary between products. Follow the instructions on the packaging.
Tapeworm treatment: Dogs can become infected with the tapeworm Dipylidium caninum if they swallow an infected flea. Your vet can advise whether your dog needs a tapeworm treatment as well as flea control.
Flea shampoos and powders may kill some adult fleas but generally do not provide reliable, long-term control. Herbal remedies and essential oils may also be ineffective or harmful.
If your dog has severe itching, hair loss or sore skin, they may also need treatment for inflammation or infection. Depending on the findings, your vet may prescribe:
Anti-itch medication to relieve inflammation and discomfort
Antibiotics, or other treatments, if a secondary bacterial skin infection is present
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How to get rid of fleas from the household
Most of the flea population in an infested home is made up of eggs, larvae and pupae in the environment, rather than adult fleas on your dog. Treating your home is therefore an important part of controlling an infestation.
It can take several weeks or sometimes a few months to get an infestation under control. You may continue to see adult fleas emerging from pupae in carpets and furnishings after treatment has started. This does not necessarily mean the treatment has failed.
Use a household flea spray when needed: Choose a product designed to kill adult fleas and/or prevent the development of immature stages. Follow the label carefully, including instructions about ventilation, drying time and when pets can re-enter treated areas.
Vacuum regularly: Especially carpets, rugs, soft furnishings, skirting boards and areas where your dog sleeps. Empty the vacuum cleaner after use and dispose of the contents safely.
Wash bedding: Wash your dog's bedding and other washable items they regularly use at the highest temperature recommended on the care label.
Treat other areas: If your dog spends time in a car, kennel or other indoor area, remember to clean these areas too.
Some dog flea treatments contain permethrin, which is highly toxic to cats and can cause serious illness. Never use a dog flea product on a cat. Check ingredients and instructions carefully, and keep cats away from treated areas for the period specified on the label.
Tips on how to prevent fleas in dogs
Use regular flea prevention: ask your vet which product is suitable for your dog and how often it should be given. Fleas can be a problem throughout the year.
Check your dog's coat: groom and brush your dog regularly, looking for live fleas, flea dirt or signs of skin irritation.
Keep the home clean: vacuum regularly, particularly around your dog's usual resting areas, and wash their bedding.
Follow advice for all household pets: make sure other dogs, cats and rabbits in the household have appropriate flea protection. The products used must be suitable for each species.
Fleas can spread from other animals or from contaminated environments, so regular prevention may still be needed even if your dog has limited contact with other pets.
What to do if you are worried about fleas
Contact your vet urgently if:
Your dog is persistently itching, scratching or biting their skin.
Your dog has significant hair loss, sore skin or widespread lesions.
Your dog is a puppy, elderly or unwell and has a heavy flea infestation.
Your dog has mild itching or a minor skin problem.
Your dog has fleas and you need advice on treating your home.
You want advice on flea prevention or how to apply a flea treatment.
You want to know how to check your dog for fleas.
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