Stronghold for cats: Stronghold and Stronghold Plus explained

What is Stronghold for cats?

Stronghold is a spot-on medicine made by Zoetis. Its active ingredient, selamectin, is absorbed through the skin into the bloodstream and then spreads back into the skin and oil glands. It kills fleas and prevents flea eggs hatching, and it also kills several internal parasites that a simple flea treatment would miss.

In the UK, Stronghold is a prescription-only veterinary medicine (POM-V). That means a vet must examine your cat before prescribing it. Vets often choose it for young kittens, cats with ear mites, or cats that need both flea and roundworm cover in one product. For an overview of all your options, see our guide to flea treatment for cats.

Stronghold vs Stronghold Plus for cats

	Stronghold	Stronghold Plus
Active ingredients	Selamectin	Selamectin + sarolaner
Fleas	Yes (kills within about 24 hours)	Yes (kills faster, usually within 12 hours)
Flea eggs hatching	Prevents	Prevents
Ticks	No	Yes
Ear mites	Yes	Yes
Roundworms and hookworms	Yes	Yes
Lungworm	No	Helps prevent some lungworm
Biting lice	Yes	Yes
Tapeworm	No	No
Minimum age	6 weeks	8 weeks
How often	Monthly	Monthly

Stronghold Plus for cats

Stronghold Plus for cats combines selamectin with sarolaner, a drug from the isoxazoline family. Sarolaner is absorbed into the blood and kills fleas and ticks when they feed. It makes Stronghold Plus a good choice for cats that roam in fields, woodland or long grass, where ticks are common, and for heavy flea infestations that need knocking down quickly.

How to apply Stronghold

1. Use the right pipette for your cat's weight, as prescribed by your vet.
2. Hold the pipette upright and press the cap down to break the seal, then remove it.
3. Part the fur at the base of the neck, in front of the shoulder blades, until you see skin.
4. Squeeze the whole tube onto the skin in one spot.
5. Avoid touching the area until dry, and don't apply to wet or damaged skin.
6. Repeat every month on the same date.

Stronghold dries quickly, often within about 30 minutes, and a bath or rain two hours after application doesn't reduce its effect on fleas, according to the manufacturer. It may leave a small clumped or greasy patch for a day.

Stronghold for ear mites

Ear mites (Otodectes cynotis) are tiny parasites that live in the ear canal. They cause intense itching, head shaking and a dark, crumbly discharge that looks like coffee grounds. Ear mites are very contagious between cats, and kittens catch them from their mother.

Stronghold is applied to the neck, not into the ears, yet it kills ear mites as it circulates. Your vet may also clean the ears and recommend a second dose a month later. Treat every cat and dog in the household at the same time, as ear mites pass easily between animals.

Does Stronghold treat worms?

Stronghold and Stronghold Plus treat roundworms (Toxocara cati) and hookworms. They do not kill tapeworms. Because cats catch the flea tapeworm by swallowing fleas, your vet may advise a separate tapeworm treatment such as a praziquantel tablet or spot-on, especially when you first get fleas under control or if your cat hunts.

Our cat worming guide explains how often to worm cats at each age, and our guide to cat worming tablets compares the options for tapeworm cover.

Stronghold for kittens

Stronghold is one of the few prescription flea treatments licensed for kittens from 6 weeks of age, which is why vets often use it when kittens are first vaccinated. It treats fleas, roundworms and ear mites, three of the most common problems in young kittens. Stronghold Plus is licensed from 8 weeks and a minimum weight. Your vet will weigh your kitten at each visit to choose the correct pipette, since kittens move up a weight band quickly.

Generic Stronghold: Selehold and Felisecto Plus

Since selamectin came off patent, other manufacturers sell equivalent products. Your vet or online pharmacy may offer:

• Selehold for cats: selamectin spot-on, equivalent to Stronghold.
• Felisecto Plus: selamectin plus sarolaner, equivalent to Stronghold Plus.

Generic products contain the same active ingredients and are approved by the Veterinary Medicines Directorate, but they still need a prescription. They can work out cheaper, so it's worth asking.

Stronghold vs Advocate vs Bravecto

	Stronghold Plus	Advocate	Bravecto spot-on
Fleas	Yes	Yes	Yes
Ticks	Yes	No	Yes
Roundworm	Yes	Yes	No (Bravecto Plus: yes)
Ear mites	Yes	Yes	No (Bravecto Plus: yes)
Tapeworm	No	No	No
How often	Monthly	Monthly	Every 12 weeks

If your cat does not need tick cover, Advocate for cats is a similar monthly option. If you'd prefer fewer doses, Bravecto for cats lasts 12 weeks. For tapeworm as well, ask about a combination such as Broadline or NexGard Combo, covered in our guide to flea and wormer products for cats.

Stronghold side effects in cats

Stronghold is widely used and well tolerated. Possible side effects include:

• Temporary clumping, greasiness or hair loss at the application site.
• Mild, short-lived itching or redness where applied.
• Drooling, especially if the cat licks the product.
• Rarely, vomiting, diarrhoea or a reduced appetite.

Stronghold Plus contains an isoxazoline, a group of drugs linked to neurological signs such as tremors, wobbliness or seizures in a small number of animals. Tell your vet if your cat has ever had a seizure, and contact them straight away if you notice any of these signs after treatment.

How much does Stronghold cost?

Because it is prescription-only, the cost of Stronghold includes the medicine and either a consultation or a prescription fee. As a rough guide, a single Stronghold or Stronghold Plus pipette costs about £8 to £15, with lower prices per dose in multipacks or through a practice health plan. Written prescriptions for online purchase often cost £10 to £20 and can cover several months of treatment. Our guide to cat vaccination costs explains how health plans bundle parasite treatment with vaccines.

Stronghold for cats with lice and mange mites

Stronghold is also licensed to treat biting lice in cats. Lice are less common than fleas but cause itching, a scruffy coat and visible white eggs (nits) stuck to the hairs, often in kittens and in older or unwell cats that groom less. One dose usually clears them, and your vet may advise a second dose a month later. Wash bedding and grooming tools at the same time.

Vets sometimes use selamectin for other skin mites as well, under their own clinical judgement. If your cat has crusty, itchy skin around the ears or face, book a check so your vet can take skin scrapings and confirm the cause before treating. Itchy skin can also be caused by flea allergy, food allergy or ringworm, which need different treatment.

Who should consider Stronghold for cats?

• Kittens from 6 weeks old that need fleas, roundworms and ear mites treated together.
• Cats with ear mites or a household where ear mites keep spreading.
• Outdoor cats in tick areas (Stronghold Plus).
• Cats that have not responded to non-prescription flea products after correct use.

Your vet will consider your cat's age, health and lifestyle before prescribing. If you live with dogs as well, remember they need their own dog-licensed products; our guide to whether dogs can get cat fleas explains the risks of cross-infestation.