Fleas and ticks don't wait for a dog to visit somewhere obviously risky - a garden, a local park and a friend's sofa can all be enough. Monthly, ongoing protection tends to work better in practice than something reached for only once a problem is already visible.

FRONTLINE Spot On Medium is a monthly spot-on for dogs between 10 and 20kg, and the pack contains 6 pipettes - six months of cover from one box. It kills fleas within 24 hours and ticks within 48 hours, which the label frames as reducing the risk of tick-borne disease, and also kills lice. FRONTLINE's checklist for use states the dog should be at least 8 weeks old and at least 2kg.

• For dogs 10-20kg
• 6 pipettes per pack - one application a month
• Kills fleas within 24 hours
• Kills ticks within 48 hours
• Also kills lice
• For dogs from 8 weeks old and at least 2kg

Before you use it. This is a veterinary-strength product with a specific weight band - it's for dogs between 10 and 20kg, not a smaller or larger dog measured by eye. Read the leaflet in the box before applying, and if your dog is close to either weight boundary or you have any doubts, check with a vet which size is right.

Who it's for: owners of a medium dog, roughly 10-20kg, wanting monthly, ongoing flea and tick cover rather than something bought only once fleas are already a problem.