POM-V Prescription Required Companion Animal

Stronghold 120 mg Spot-on Solution for Dogs 10.1–20.0 kg

Active ingredient: Selamectin

Form

Spot-on

Species

Dogs

Manufacturer

Zoetis UK Limited

VMD MA No.

42058/5060

What it's used for

•Ctenocephalides spp. for one month following a single administration. This is as a result of the adulticidal, larvicidal and ovicidal properties of the pr...

Full indications, dosage and side effects ↓

View official SPC (PDF)

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Paying less for Selamectin

1

Ask your vet for a written prescription

They must provide one on request. Under the CMA Order the fee is capped at £21 from 2027.
2

Fill it at a registered online retailer

The CMA found online pharmacies 50–60% cheaper than practice dispensing on common medicines — typically £200–£300 a year.

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Prescription required

Your vet must provide a written prescription on request. You can then purchase from any licensed online retailer.

Clinical information

Stronghold 120 mg Spot-on Solution for Dogs 10.1–20.0 kg — SPC Details

Source: VMD Summary of Product Characteristics (SPC). Last updated 26 Mar 2026.

•Ctenocephalides
spp. for one month following a single administration. This is as a result of the
adulticidal, larvicidal and ovicidal properties of the product. The product is ovicidal for
3 weeks after administration. Through a reduction in the flea population, monthly
treatment of pregnant and lactating animals will also aid in the prevention of flea
infestations in the litter up to seven weeks of age. The product can be used as part
of a treatment strategy for flea allergy dermatitis and through its ovicidal and
larvicidal action may aid in the control of existing environmental flea infestations in
areas to which the animal has access.
•Dirofilaria immitis with monthly
administration. The veterinary medicinal product may be safely administered to
animals infected with adult heartworms, however, it is recommended, in accordance
with good veterinary practice, that all animals 6 months of age or more living in
countries where a vector exists should be tested for existing adult heartworm
infections before the administration of the veterinary medicinal product. It is also

Revised: March 2025
AN: 03745/2024
recommended that dogs should be tested periodically for adult heartworm infections,
as an integral part of a heartworm prevention strategy, even when the veterinary
medicinal product has been administered monthly. This product is not effective
against adult D. immitis.
• (Otodectes cynotis).
• Treatment of biting lice infestations (Trichodectes canis
• Treatment of sarcoptic mange (caused by Sarcoptes scabiei
• Treatment of adult intestinal roundworms (Toxocara canis).

Do not use in animals under 6 weeks of age.

Dogs:
Rare
(1 to 10 animals / 10,000 animals
treated):
application site hair
changes
Very rare
(<1 animal / 10,000 animals
treated, including isolated reports):
neurological signs (including
seizures
)
Local temporary clumping of the hair at the application site and/or an occasional
appearance of a small quantity of a white powder which typically disappear within 24
hours of treatment administration and does not affect either the safety or efficacy of
the veterinary medicinal product.
Reversible as with other macrocyclic lactones.
Reporting adverse events is important. It allows continuous safety monitoring of a
veterinary medicinal product. Reports should be sent, preferably via a veterinarian,
to either the marketing authorisation holder <or its local representative or the national
competent authority via the national reporting system>. See also the last section of
the package leaflet for respective contact details.

Animals may be bathed 2 hours after treatment without loss of efficacy.
Do not apply when the animal’s hair coat is wet. However, shampooing or soaking
the animal 2 or more hours after treatment will not reduce the efficacy of the product.
For ear mite treatment, do not apply directly to the ear canal.
It is important to apply the dose as indicated to minimise the quantity that the animal
can lick off. If significant licking does occur, a brief period of hypersalivation may
rarely be observed in cats.

Special precautions for use in animals
This veterinary medicinal product is to be applied to the skin surface only. Do not
administer orally or parenterally.
Keep treated animals away from fires and other sources of ignition for at least 30
minutes or until the hair coat is dry.
Special precautions to be taken by the person administering the veterinary medicinal
product to animals
This product is highly flammable; keep away from heat, sparks, open flames or other
sources of ignition.
Do not smoke, eat or drink while handling the product.
Wash hands after use and wash off any product in contact with the skin immediately
with soap and water. In case of accidental eye exposure, flush the eyes immediately
with water, seek medical advice immediately and show the package leaflet or the
label to the physician.
Avoid direct contact with treated animals until the application site is dry. On the day
of treatment, children must not handle treated animals and the animals should not be

Revised: March 2025
AN: 03745/2024
permitted to sleep with their owners, especially children. Used applicators should be
disposed of immediately and not left within the sight or reach of children.
People with sensitive skin or known allergy to veterinary medicinal products of this
type should handle the veterinary medicinal product with caution.
Other precautions
The veterinary medicinal product should not enter water courses as this may be
dangerous for fish and other aquatic organisms.
Do not allow treated animals to bathe in water courses until at least two hours after
treatment administration.

In extensive field testing no interactions between this veterinary medicinal product
and routinely used veterinary medicinal products or medical or surgical procedures
were observed.

Revised: March 2025
AN: 03745/2024

Do not store above 30 °C. Store in the original package in a dry place.

Not applicable.
5.

This information is sourced from the official Summary of Product Characteristics (SPC) published by the Veterinary Medicines Directorate (VMD). It is provided for informational purposes only and does not replace professional veterinary advice. Always consult your vet before administering any medication.

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Your Rights

Prescription Fee Cap Can My Vet Refuse a Prescription? Buy Pet Medication Online

Same active ingredient

Other Products Containing Selamectin

These products share the same active ingredient and may be suitable alternatives. Always consult your vet.