A once-a-month flea treatment only works on the months it actually gets used, and the pipette that sits forgotten at the back of a drawer causes more reinfestations than resistance ever does.

FRONTLINE Spot On is a fipronil-based spot-on, applied by snapping the tip off the sealed pipette and parting the fur at the base of the neck so the liquid reaches skin rather than sitting on the coat. Frontline's own figures are that it kills fleas within 24 hours and ticks within 48, and it is also effective against lice. This pack holds three pipettes, one per month; Frontline also sell it as a single pipette or a six-pack for owners who want to buy less often.

• Active ingredient: fipronil
• Kills fleas within 24 hours and ticks within 48
• Also effective against lice
• 3 pipettes per pack (1- and 6-dose packs also available)
• Comes in three sizes — small, medium and large — banded to a dog's weight
• Frontline's own checklist requires a dog to be at least 8 weeks old and 2kg

What the pack does not decide for you. Frontline's instructions say do not bathe or let a dog swim for 2 days after application, and it should not be used on rabbits. If a dog seems unwell, their guidance is to check with a vet before applying rather than after. Children should not play with or sleep against a treated dog until the application site has dried.

Who it's for: owners running a proper monthly flea and tick routine who would rather buy three months at once than remember to reorder every four weeks.