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
Free standard delivery over £50
Unbranded, secure packaging guaranteed
5% off your first order
When you sign up
Registered Veterinary Retailer
Genuine pet medicine
Stronghold Plus for Cats
From Price range: £19.15 through £36.75
- Prescription Required
Stronghold Plus for Cats
From Price range: £19.15 through £36.75
Stronghold Plus for cats is a monthly prescription flea and tick treatment. It adds sarolaner to Stronghold’s selamectin, which brings ticks into cover alongside other parasites. Kills fleas on the cat within 24 hours, with activity against new fleas for 5 weeks.
- Treats four tick species
- Reduces the risk of flea-borne tapeworm for one month
- Treats notoedric mange
- Monthly for fleas, ticks and heartworm prevention
For cats from 8 weeks old and 1.25 kg, in three weight bands up to 10 kg
Treats ear mites, biting lice, roundworms and hookworms, and prevents heartworm
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 Plus for cats is a monthly prescription flea and tick treatment. It adds sarolaner to Stronghold’s selamectin, which brings ticks into cover alongside other parasites. Kills fleas on the cat within 24 hours, with activity against new fleas for 5 weeks.
- Treats four tick species
- Reduces the risk of flea-borne tapeworm for one month
- Treats notoedric mange
- Monthly for fleas, ticks and heartworm prevention
For cats from 8 weeks old and 1.25 kg, in three weight bands up to 10 kg
Treats ear mites, biting lice, roundworms and hookworms, and prevents heartworm
Product Details
What is Stronghold Plus?
Stronghold Plus is a topical spot-on solution for cats containing selamectin and sarolaner. Your vet may prescribe Stronghold Plus if your cat has, or is at risk from, ticks and another parasite at the same time, such as fleas, ear mites or worms. If ticks are the only problem, a treatment that doesn’t need a vet prescription may suit.
Stronghold vs Stronghold Plus
Same maker, same selamectin base. Stronghold Plus adds a second active, sarolaner, which brings ticks onto the licence. It’s for cats only.
| Stronghold | Stronghold Plus | |
|---|---|---|
| Active ingredients | Selamectin | Selamectin + sarolaner |
| Species | Cats and dogs | Cats only |
| Ticks on the licence | No | Yes |
| Legal category | POM-V | POM-V |
For dog strengths and the full original range, see our Stronghold spot-on page.
Safety information
For your cat
- Not for cats with other illnesses, or cats that are weak and underweight for their size and age.
- Not for cats with a known allergy to any ingredient.
- Uncommon (1 to 10 in 1,000 cats): mild itching, mild to moderate hair loss or redness at the application site, and drooling.
- Very rare (under 1 in 10,000): fits, wobbliness, vomiting or diarrhoea, mostly short-lived.
- Pregnant, nursing or breeding cats: safety of the combined product isn’t established. Your vet decides.
For people at home
- Harmful if swallowed. Keep pipettes in the pack until use, out of children’s reach, and throw used pipettes away straight after.
- Children shouldn’t play with a treated cat for 4 hours after treatment. Treating in the evening is recommended.
- 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 the cat away from fires and flames for at least 30 minutes, or until the coat is dry.
- Avoid skin and eye contact, and avoid touching the treated area until it’s dry. Wash your hands after use.
Full warnings are in the Stronghold Plus 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 Plus for cats: common questions
Can I buy Stronghold Plus 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. A seller offering it without one isn’t following VMD rules.
What does Stronghold Plus for cats treat?
Ticks plus at least one of fleas, ear mites, biting lice, notoedric mange, adult roundworms or adult hookworms. It’s also licensed to prevent heartworm disease, to reduce the risk of flea-borne tapeworm, and as part of a plan for flea allergy dermatitis. The full list is in the datasheet.
Does Stronghold Plus treat worms?
Roundworms (Toxocara cati) and hookworms (Ancylostoma tubaeforme) only, both adult stages.
It doesn’t treat tapeworm. It does reduce the risk of flea-borne tapeworm (Dipylidium caninum) for one month after treatment, by killing the fleas that carry it. Ask your vet if your cat needs a separate tapeworm treatment.
How often is Stronghold Plus used?
Monthly for fleas, ticks and heartworm prevention. For worms, lice, ear mites and mange it’s usually a single dose, with a vet check 30 days after ear mite treatment. Follow your vet’s prescription label.
How long does Stronghold Plus take to work?
For fleas, onset is within 24 hours, for 5 weeks after application. For Ixodes ricinus ticks, onset is within 24 hours of the tick attaching, for one month.
Which Stronghold Plus strength does my cat need?
It’s set by weight. 15mg/2.5mg for 1.25 kg to 2.5 kg, 30mg/5mg for over 2.5 kg to 5 kg, 60mg/10mg for over 5 kg to 10 kg. Cats over 10 kg need a combination your vet will prescribe.
Can kittens use Stronghold Plus?
From 8 weeks old, as long as the kitten weighs at least 1.25 kg. Below either limit, it isn’t licensed.
Is Stronghold Plus spot-on safe for cats?
In safety testing, kittens from 8 weeks old were given up to 5 times the top recommended dose, 8 times at 28-day intervals, with no clinically significant reactions. One cat at 5 times the dose showed short-lived sensitivity to touch, raised fur, dilated pupils and mild tremor, which resolved without treatment. Your vet will check it’s right for your cat.
Instructions
How to use Stronghold Plus
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, and follow the label and your prescription.
Part the hair to show a small patch of skin, place the tip on the skin and squeeze firmly 3 to 4 times to empty it in one spot. Don’t massage it in. Don’t apply to a wet coat, and for ear mites, don’t put it into the ear canal.
For information on safe use, read the Stronghold Plus datasheet.
Sizes
Stronghold Plus Pack sizes and strengths
Stronghold Plus is available in packs of 3 and 6 pipettes.
| Strength | Cap colour | Cat weight | Pack sizes |
|---|---|---|---|
| Stronghold Plus 15 mg/2.5 mg spot-on solution for cats ≤2.5 kg | Yellow | From 1.25 to 2.5 kg (small cat) | 3 or 6 pipettes |
| Stronghold Plus 30 mg/5 mg spot-on solution for cats >2.5–5 kg | Orange | Over 2.5 to 5 kg (Medium Cats) | 3 or 6 pipettes |
| Stronghold Plus 60 mg/10 mg spot-on solution for cats >5–10 kg | Green | Over 5 to 10 kg (Large Cats) | 3 or 6 pipettes |
For information on safe use, read the Stronghold Plus datasheet.
Key Benefits
Key benefits of Stronghold Plus for cats
Parasite cover in one spot-on
- Ticks plus fleas, ear mites, biting lice, adult roundworms and adult hookworms
- Treats four tick species
- Treats notoedric mange
- Prevents heartworm disease
- Reduces the risk of flea-borne tapeworm for one month
Speed and duration of protection
- Kills fleas on the cat within 24 hours
- Activity against new fleas for 5 weeks
- Ixodes ricinus ticks: onset within 24 hours of the tick attaching, for one month
Easy to fit to your cat
- One pipette once a month for fleas, ticks and heartworm prevention
- Three weight bands, from 1.25 kg up to 10 kg
- For cats from 8 weeks old and 1.25 kg
- Packs of 3 and 6 pipettes
Prescription only (POM-V). Use the strength that matches your cat’s current weight, and follow the label and your prescription.
Ingredients
Active ingredient
Sarolaner, selamectin
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).
Latest Blogs
Can Cats Get Fleas in Winter? Surprising Facts Every Owner Should Know
Can cats get fleas in winter? Yes, they absolutely can. Fleas persist throughout winter, and in some homes the problem actually becomes more noticeable during this time.
April 28, 2026
How Often Does a Dog Need Worming? Vet Schedule UK
Most UK adult dogs need worming every three months — monthly if they scavenge, hunt or eat raw food. Vet-reviewed schedule by age and lifestyle.
August 28, 2026