FRONTLINE

Frontline Flea, Tick & Worming Treatments for Dogs and Cats

Frontline® is a fipronil-based flea and tick range manufactured by Boehringer Ingelheim, and one of the most established veterinary parasite treatments sold in the UK for cats and dogs. The range spans spot-on treatments (Frontline Spot On, Frontline Plus and Frontline Combo), a fast-acting dogs-only option (Frontline Tri-Act), an oral wormer, and both a direct-to-pet spray and a household environmental spray.

Compare the Frontline Range

Not every product in the range works the same way or covers the same parasites. Some treat fleas and ticks only; others also stop flea eggs and larvae from developing; the oral Wormer tablets target intestinal worms rather than external parasites at all. The sections below set out exactly what each product covers, who it is suitable for, and how to use it safely — so you can match the right treatment to your pet before you buy.

Fipronil, the active ingredient shared by Spot On, Plus and Combo, kills fleas within 24 hours and ticks within 48 hours of contact.

Which Frontline Product Does My Pet Need?

Frontline for Cats

My pet is a cat or kitten

Frontline Spot On and Frontline Plus are both licensed for cats and kittens weighing over 1 kg and aged 8 weeks or older. Frontline Plus is the stronger option of the two — it contains an insect growth regulator (S-methoprene) that stops flea eggs and larvae from developing, breaking the flea life cycle rather than just killing adult fleas already on your cat.

Frontline Combo for cats requires a prescription (POM-V). If your vet has recommended it, you can upload your prescription at checkout.

Never use Frontline Tri-Act on cats. It is formulated for dogs only and contains permethrin, which can cause serious, often fatal adverse reactions in cats.

Frontline for Dogs

My pet is a dog or puppy

Frontline Spot On, Frontline Plus and Frontline Combo are all suitable for dogs and puppies from 8 weeks of age and weighing at least 2 kg. As with cats, Frontline Plus is the more complete over-the-counter treatment — covering flea eggs and larvae as well as adult fleas and ticks.

Frontline Tri-Act is dogs-only and provides additional repellent action against ticks, biting flies, stable flies, mosquitoes, and sandflies. It is an ideal option for dogs that spend time in woodland, long grass, or areas with high tick activity.

You must select the correct weight-band pack for your dog. Using the wrong size is unsafe and reduces efficacy. The available weight bands are:

• Toy/Extra Small dogs: 2–5 kg
• Small dogs: 5–10 kg
• Medium dogs: 10–20 kg
• Large dogs: 20–40 kg
• Extra large dogs: 40–60 kg (Dogs over 60 kg require a specific combination of two pipettes)

Frontline Worming

My Pet Has Worms

Frontline Spot On, Frontline Plus and Frontline Tri-Act do not treat intestinal worms. If your pet needs worming, you need Frontline Wormer, which is a separate oral tablet product. The dog tablet covers roundworms, tapeworms, hookworms, and whipworms. The cat tablet covers roundworms and tapeworms.

Frontline Wormer is generally given every three months. However, if your pet has fleas, it is particularly important to also treat for tapeworms — fleas carry tapeworm larvae, and a pet that swallows an infected flea while grooming will develop a tapeworm infection. Running a flea treatment and a worming schedule together provides complete protection.

Flea Infestation in the Home

My Home Has a Flea Infestation

Only around 5% of a flea infestation lives on your pet at any one time. The other 95% — eggs, larvae and pupae — are in your carpets, soft furnishings and pet bedding. Treating your pet alone will not clear your home.

Frontline HomeGard is a household flea spray for use on carpets, rugs, upholstery and pet sleeping areas. It is a biocide product, not a veterinary medicine, and must never be applied to animals. Use it alongside a spot-on treatment on your pet for complete environmental control.

Frontline Safety and Responsible Use

Weight and Age Minimums

Always weigh your pet before purchasing and select the correct pack. The minimum requirements are:

• Cats and kittens: over 1 kg, aged 8 weeks or older
• Dogs and puppies (Spot On/Plus/Combo/Tri-Act): over 2 kg, aged 8 weeks or older
• Dogs and puppies (Frontline Wormer): over 3 kg, aged 8 weeks or older

Never Use on Rabbits

Frontline products must never be applied to rabbits. Serious adverse reactions, including fatalities, have been reported in rabbits treated with fipronil-based products. This applies to all formats in the range.

Never Use Dog-Only Products on Cats

Frontline Tri-Act is licensed for dogs only. It must never be applied to cats. If you have both dogs and cats in the same household, keep treated dogs away from cats until the application site is completely dry to prevent accidental grooming.

The 48-Hour Bathing and Swimming Rule

Do not bathe your pet, apply shampoo, or allow them to swim for 48 hours after application. Water exposure before the treatment has spread through the skin's natural oils will significantly reduce its effectiveness.

How to Apply a Spot-On Correctly

Incorrect application is the most common reason Frontline treatments appear to stop working. Apply to the skin, not the fur:

1. Part the fur at the back of the neck, between the shoulder blades, until the skin is visible.
2. Place the pipette tip directly against the skin.
3. Squeeze the pipette firmly to empty the full contents directly onto the skin.
4. Do not rub it in — the treatment spreads through the skin's natural oils on its own.

Do Not Use Alongside Other Topical Flea Treatments

Do not apply Frontline at the same time as another spot-on or topical flea product. If you are switching treatments, allow the current one to complete its full 4-week cycle before starting a new product.

Environmental Disposal

Empty pipettes contain traces of fipronil, which is highly toxic to aquatic organisms. Dispose of used pipettes directly in household waste — do not rinse them, and do not dispose of them in drains, ponds, or waterways.

Interactions and Health Conditions

Do not use any Frontline product on a sick, feverish, or convalescing animal without veterinary advice. If your pet has a known hypersensitivity to fipronil or any of the excipients, do not use.

Fleas, Ticks and Worms — Why You Often Need to Treat for Both

How Fleas Spread Tapeworms

Fleas are not just an irritation — they are a direct route for tapeworm infection. Tapeworm eggs are carried inside flea larvae. When a dog or cat grooms itself and swallows an infected flea, the tapeworm completes its life cycle inside the pet's gut. A pet can have a tapeworm infection with no visible symptoms.

If you are treating your pet for fleas, it is good practice to also run a worming course, particularly if you have seen live fleas on your pet or in your home. Frontline Wormer and any of the Frontline spot-on treatments can be used together — they are separate products targeting separate parasite types and do not interact.

Does Frontline Cover Lungworm?

No. None of the Frontline range covers lungworm (Angiostrongylus vasorum). Lungworm is carried by slugs and snails and is a potentially serious, sometimes fatal condition in dogs. It is not covered by fipronil-based products or by Frontline Wormer.

If your dog is at risk of lungworm — particularly if they are known to eat slugs, snails, or grass — speak to your vet. Lungworm prevention requires a prescription-only product containing moxidectin or milbemycin oxime.