Flea treatment for dogs: spot-ons, tablets and what to expect

Spot-ons: how they work and when they suit

Spot-on liquids are applied to the skin at the back of the neck, then spread through the skin oils over the following days. Most contain an insecticide that kills adult fleas, often combined with an insect growth regulator that stops eggs from developing.

They are easy to use at home, but they take time to distribute across the coat and may be less reliable if the dog is bathed or swims frequently straight after application. Many owners choose them for a straightforward monthly routine.

• Kills adult fleas over hours to a day depending on the active ingredient.
• Growth regulators help break the life cycle by stopping eggs and larvae from maturing.
• Best for dogs that tolerate handling and are not washed immediately after treatment.

Tablets and chews: speed of action

Oral flea treatments enter the bloodstream and kill fleas when they bite. Some act within 30 minutes and can kill nearly all adult fleas on the dog within a few hours. That speed is useful when an infestation is severe and the owner wants rapid relief.

Oral products do not leave a residue on the coat, so they are unaffected by bathing or swimming. The downside is that they do not usually provide a persistent environmental effect; additional household measures may be needed to clear eggs and larvae.

• Fast onset makes tablets useful for heavy, active infestations.
• No coat residue, so bathing and swimming are not a concern.
• Most need repeating on the schedule stated on the label.

Treating the environment, not just the dog

Flea eggs and larvae live in carpets, bedding, car upholstery and soft furnishings. Treating only the dog will leave the next generation of fleas waiting to hatch, which is why reinfestation seems to keep happening.

Hot-washing bedding at the highest safe temperature, vacuuming thoroughly including edges and skirting boards, and using an appropriate household spray can all reduce the environmental burden. Flea pupae are resistant to sprays, so repeated vacuuming over several weeks is usually necessary.

• Wash all pet bedding weekly during an active infestation.
• Vacuum daily if possible, and discard the bag or empty the cylinder outside.
• Treat every dog and cat in the household, not just the one with visible fleas.

UK legal classes and buying safely

Flea treatments in the UK are classified according to the Veterinary Medicines Directorate framework. Some products are available from a registered retailer with advice from an SQP, while others require a prescription from a vet. Buying from an unregistered overseas seller risks counterfeit, unlicensed or incorrectly dosed products.

Always check the VMD register of accredited internet retailers if you are buying online, and choose the dose for your dog's weight range exactly as stated on the label.

When to speak to your vet

Puppies, elderly dogs, pregnant bitches, and dogs with existing health conditions should have product choice confirmed by a vet. The same applies if the skin is sore, infected, or if the dog has had a previous reaction to a parasite treatment. Persistent infestation despite correct treatment may mean the household is repeatedly being reseeded from wildlife or an untreated pet.

From treatment to prevention

Once the active infestation is under control, a repeat-care plan is the most reliable way to stop the cycle restarting. Regular treatment on schedule, matched to the dog's lifestyle and weight, keeps newly hatching fleas from establishing again. Our repeat-care model is designed to make that monthly rhythm simple and consistent.