Approaches to tackling fleas and ticks include prevention and cure, both on the animal and in the home and wider environment. Preparations can act:

• As a repellent to deter the flea or tick from being attracted to the animal, or reduce the risk of the parasite biting the pet
• As an acaricide/insecticide to kill the parasite
• As an insect growth regulator (IGR) to disrupt the parasite lifecycle.¹⁰

Many products are intended for topical application and can be applied as a concentrated liquid to spot on the coat, as solutions or powders, or as impregnated collars. Others are for systemic use, with the agent being given in an oral format or injected, such as fluralaner or lufenuron.

While targeting fleas and lice, preparations can often have additional ingredients to tackle secondary infestations, such as the tapeworms carried on fleas, or be licensed for additional indications such as lice, blow flies, ear mites, mange, mosquitoes, stable flies, sand flies and worm infestations.¹⁰

Products should only be used for specified animal types and for specified conditions; brands may contain different chemicals or strengths across the product range, depending on which animal they are licensed to treat. Products may not be suitable for smaller animals, and higher strength preparations intended for larger dogs may be contraindicated in small dogs such as chihuahuas, and could be toxic to cats or rabbits.

Modes of action can differ, especially the point in the parasites’ life cycle at which the chemical takes effect. If a product works by preventing the development of flea larvae, it will not kill adult fleas, so it may be necessary to continue or repeat treatment for a couple of months, or use two products together.

Owners should seek a vet’s advice before treating the pet with flea or tick preparations if the animal is:

• Particularly young (eg, puppies under eight weeks)
• Small for its genus (eg, dogs weighing under 2kg)
• Pregnant
• Suckling its young.¹⁰