Can Dogs Get Fleas in Winter? The Truth Most Owners Miss
Yes, dogs can get fleas in winter. Many owners have seen infestations during the winter months that were even worse than in summer.
April 20, 2026
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Stronghold for Cats | Spot-On Solution
From Price range: £18.56 through £82.91
- Prescription Required
Stronghold for Cats | Spot-On Solution
From Price range: £18.56 through £82.91
Stronghold for cats is a monthly prescription spot-on containing selamectin. It treats and prevents fleas, treats ear mites, biting lice, roundworms and hookworms, and prevents heartworm. Part of the Stronghold range from Zoetis.
Topical spot-onPOM-V itemOne pipette, once a month
- Kills adult fleas, flea eggs and larvae
- Treats adult roundworms and hookworms
- Prevents heartworm disease
AgeSuitable for kittens from 6 weeks old
Strengths15mg for kittens and cats up to 2.5kg · 45mg for cats 2.6 to 7.5kg
BreedingCan be used in pregnant, lactating and breeding cats
Jump to product details ↓Treating a dog? See Stronghold for dogs →
Order Monday to Friday before 14:00pm to guarantee next
day delivery.
Please select size and quantity as shown in your prescription.
Ordering Prescription-Only Products
This item requires a current prescription from your vet before we can dispatch it. The good news? Sorting it out is simple and only takes a moment.
- Select or register your pet
- Attach a clear image or PDF of the prescription
- Complete your order at checkout
As soon as your prescription reaches us, our team will verify the details and get your pet’s treatment posted out to you.
Order Monday to Friday before 14:00pm to guarantee next
day delivery.
Product Features
Stronghold for cats is a monthly prescription spot-on containing selamectin. It treats and prevents fleas, treats ear mites, biting lice, roundworms and hookworms, and prevents heartworm. Part of the Stronghold range from Zoetis.
Topical spot-onPOM-V itemOne pipette, once a month
- Kills adult fleas, flea eggs and larvae
- Treats adult roundworms and hookworms
- Prevents heartworm disease
AgeSuitable for kittens from 6 weeks old
Strengths15mg for kittens and cats up to 2.5kg · 45mg for cats 2.6 to 7.5kg
BreedingCan be used in pregnant, lactating and breeding cats
Jump to product details ↓Treating a dog? See Stronghold for dogs →
Product Details
We can only dispatch this medicine once we’ve received and approved a valid veterinary prescription.
What is Stronghold for cats?
Stronghold spot-on for cats is a prescription-only (POM-V) flea treatment made by Zoetis. Its active ingredient, selamectin, belongs to the avermectin family. It is absorbed through the skin and spreads through the body, where it disrupts parasites’ nerve signals, which paralyses or kills them.
What does Stronghold for cats treat?
- Fleas (Ctenocephalides species): kills adult fleas, flea eggs and larvae, and prevents new infestations for a month. It stops flea eggs hatching for 3 weeks after each dose.
- Ear mites (Otodectes cynotis)
- Biting lice (Felicola subrostratus)
- Roundworms (adult Toxocara cati)
- Hookworms (adult Ancylostoma tubaeforme)
- Heartworm (Dirofilaria immitis): prevents heartworm disease with a monthly dose, but isn’t effective against adult heartworms
- Flea allergy dermatitis: can be used as part of a treatment plan
Treating a pregnant or lactating cat monthly also helps protect her kittens from fleas until they’re 7 weeks old.
Stronghold doesn’t cover ticks or tapeworms in cats. Your vet may add a separate treatment from our flea, tick and wormer range.
Stronghold or Stronghold Plus?
Same maker, same selamectin base. If your cat picks up ticks outdoors, your vet may prescribe Stronghold Plus for cats, which adds sarolaner for tick cover. Stronghold Plus is for cats from 8 weeks old and 1.25kg.
| Stronghold | Stronghold Plus | |
|---|---|---|
| Active ingredients | Selamectin | Selamectin + sarolaner |
| Ticks on the licence | No | Yes |
| Minimum age | 6 weeks | 8 weeks and 1.25kg |
| Legal category | POM-V | POM-V |
For dog strengths and the full range, see our Stronghold spot-on page.
Safety information
For your cat
- Not for kittens under 6 weeks old.
- Not for cats that are ill, weak or underweight for their size and age.
- Apply to the skin only, never by mouth or injection, and only on a dry coat.
- Rare (1 to 10 in 10,000 cats): mild, short-lived hair loss or clumping of the hair where it was applied, sometimes with a little white powder. Clumping usually clears within 24 hours.
- Very rare (under 1 in 10,000): short-lived skin irritation at the spot, or nervous signs, including fits.
- If your cat licks the spot a lot, brief drooling can rarely happen. Try to stop your cat licking it until it’s dry.
- Pregnant, lactating or breeding cats: can be used.
For people at home
- On treatment day, children shouldn’t handle the treated cat.
- Treated cats shouldn’t sleep in the same bed as their owner on treatment day, and especially not in a child’s bed.
- Highly flammable. Keep your cat away from fires and flames for at least 30 minutes, or until the coat is dry.
- Don’t smoke, eat or drink while applying it.
- Avoid direct contact with your cat until the application site is dry.
- Wash your hands after use.
Full warnings are in the Stronghold datasheet. Contact your vet if you notice any reaction.
Legal category: POM-V
View the Summary of Product Characteristics (SPC) information for this product
Stronghold for cats FAQs
Can I buy Stronghold for cats without a vet prescription in the UK?
No. It’s a POM-V medicine, and any UK seller needs a valid written prescription from your vet before it can be supplied.
Which Stronghold strength does my cat need?
Pick the pipette by your cat’s weight on the day you treat: 15mg for kittens and cats up to 2.5kg, 45mg for cats from 2.6 to 7.5kg, and 60mg for cats from 7.6 to 10kg. Cats over 10kg need a combination of pipettes, prescribed by your vet.
Can kittens use Stronghold?
Yes, from 6 weeks old, using the 15mg pipette up to 2.5kg. Kittens grow quickly. Weigh them before each monthly dose and move up to 45mg once they pass 2.5kg.
Does Stronghold kill ticks on cats?
No. Stronghold isn’t licensed to kill, treat or prevent ticks. For tick cover, your vet may prescribe Stronghold Plus.
Does Stronghold worm cats?
It treats adult roundworms (Toxocara cati) and adult hookworms (Ancylostoma tubaeforme), and prevents heartworm disease. It doesn’t treat tapeworms.
Does Stronghold treat ear mites in cats?
Yes, with one dose applied to the neck, never into the ear. Gently clean loose debris from the ear canal at treatment. A vet check 30 days later is recommended, as some cats need a second treatment.
How often is Stronghold used on cats?
Monthly for fleas, starting a month before fleas become active, and monthly for heartworm prevention. Ear mites, biting lice, roundworms and hookworms need a single dose. Follow your vet’s prescription label.
Can I use Stronghold on a pregnant cat?
Yes. It can be used in pregnant, lactating and breeding cats. Monthly treatment also helps protect her kittens from fleas until they’re 7 weeks old.
Can I bath my cat after Stronghold?
Yes, from 2 hours after treatment, with no loss of effect.
Is Stronghold safe for cats?
In safety studies, cats given 10 times the recommended dose showed no undesirable effects. Your vet will check it’s right for your cat.
Instructions
How to use Stronghold for cats
Apply one pipette to the skin at the base of your cat’s neck, in front of the shoulder blades, once a month or as your vet directs. Use the strength that matches your cat’s current weight.
Hold the pipette upright and press the cap firmly to break the seal, then remove the cap. Part the hair to show a small patch of skin. Touch the tip to the skin and squeeze firmly to empty it in one spot, without rubbing it in or touching the liquid. Don’t apply to a wet coat, and for ear mites, don’t put it into the ear canal.
For more on keeping fleas out of your home, read our flea and tick guides.
For information on safe use, read the Stronghold datasheet.
Sizes
Stronghold for cats pack sizes and strengths
Stronghold for cats is available in packs of 3, 6 or 15 pipettes, depending on the strength.
| Strength | Cap colour | Cat weight | Pack sizes |
|---|---|---|---|
| Stronghold 15mg for kittens and cats (0.25 ml) | Rose | Up to 2.5 kg | 3 or 15 pipettes |
| Stronghold 45mg for cats (0.75 ml) | Blue | 2.6 to 7.5 kg | 3 or 6 pipettes |
For cats over 7.5 kg, ask your vet which pipette or combination they need.
Key Benefits
Key features of Stronghold for cats
Parasite cover in one spot-on
- Fleas, ear mites, biting lice, adult roundworms and adult hookworms
- Prevents heartworm disease
- Can be part of a flea allergy dermatitis plan
Dosing and strengths
- One pipette once a month for fleas and heartworm prevention
- Two strengths, from kittens up to 7.5 kg
- Colour-coded caps by weight
- For cats from 6 weeks old, including pregnant, lactating and breeding cats
Prescription only (POM-V). Use the strength that matches your cat’s current weight, and follow the label and your prescription. Browse more cat medicines.
Ingredients
How it works to order pet prescription medications online
Choose your
treatment
Select the treatment you would like to order
Upload a prescription copy at
the checkout
Provide all the information about your pet
Express
Delivery
Your order will be sent in discreet packaging.
Frequently asked questions
Do I need a prescription to buy POM-V pet medicines online?
Yes. POM-V items require a valid prescription from your UK vet.
How do I send you my prescription?
Upload your prescription during checkout.
I uploaded a photo—why was it rejected?
Photos must be clear. If details are wrong or expired, orders can’t be processed. This is standard across UK pet pharmacies.
Can my vet refuse to give me a written prescription?
No. Under UK law, vets must provide a written prescription if you request one for a POM-V medicine. They may charge a reasonable fee for issuing it, but they cannot refuse. This allows you to choose where to buy your pet’s medication, whether directly from your vet or from a registered UK pharmacy such as Ashcroft 4 Pets.
How long is my prescription valid?
In the UK, most POM-V prescriptions are valid for 6 months, unless your vet specifies a shorter duration. Prescriptions for Schedule 2 or 3 controlled medicines are usually valid for 28 days and are not repeatable. At Ashcroft 4 Pets, we follow these same UK veterinary guidelines to ensure your pet’s medication is dispensed safely and legally.
How can I be sure Ashcroft 4 Pets is a safe and legitimate online pet pharmacy?
At Ashcroft 4 Pets, we are a fully VMD-registered and accredited online retailer. This means every prescription and over-the-counter pet medicine we supply is safe, genuine, and dispensed according to UK law.
We follow all Veterinary Medicines Directorate (VMD) rules, and our team checks every prescription carefully before processing. You can order with confidence, knowing your pet’s health is in the hands of experts and all medicines are traceable, legally supplied, and authentic.
How long can I continue ordering with my repeat prescription?
In the UK, most repeat prescriptions for POM-V medicines are valid for up to 6 months from the date your vet issues them. You can order multiple times within this period if your vet has authorised repeats.
For controlled medicines (Schedule 2 or 3), the prescription is valid for 28 days only and cannot be repeated. These medicines are strictly regulated due to their potential for misuse.
At Ashcroft 4 Pets, we follow UK law carefully, ensuring all prescriptions are dispensed safely, legally, and in the exact amounts prescribed.
What about “human” medicines prescribed for pets?
If your vet prescribes a human medicine for your pet under the Cascade, we can usually dispense against that prescription (with the right checks).
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