The cat flea, Ctenocephalides felis, is the most common flea species in Britain.⁴ Bird fleas are next most significant, followed by the less common dog flea, C. canis. Cat fleas will feed on over 50 different types of animal, including humans. Human fleas (Pulex irritans) are also happy to feed on people and pets.

During a flea infestation, only a small proportion of the population will be on the host animal, with potentially 95 per cent of the fleas in the surrounding environment, for example, as larvae in the pet’s bedding and carpets.⁵ This is where blood-containing flea faeces can accumulate, and it is the main dietary source of blood for larvae.

Ticks – or rather the diseases caused by them – are becoming more common in the UK. Possible reasons include a growing deer population, climate change, farming practices and wildlife management. Use of pet passports means pets are bringing back more exotic ticks when they return from warmer European climates.^2,3

Hard tick species, especially Ixodes spp, are most likely to be found on pets – and humans – across the UK. In England, the sheep tick is on the increase, moving northwards from its stronghold in the Home Counties to the Midlands, but is also widespread across Scotland, Wales and England’s northern moorlands. Some tick species originating on mainland Europe have also become established in parts of southern England and Wales, possibly surviving due to recent relatively mild winters.^1,5

• In a household with several pets, assume that if one has fleas the rest will, too. Ticks might only be found on one animal at a time, but shared habitats might mean other pets will be exposed.
• Regularly grooming the pet with a fine-toothed flea comb can help spot fleas or ticks early on. Daily grooming is recommended if an infestation is suspected.
• Household flea sprays can kill off larvae and adults, and regular vacuuming will help remove unhatched eggs and nutrients for larvae; pet owners should then empty the vacuum cleaner immediately afterwards – away from the house as the larvae will still be alive.
• Pet bedding should be washed weekly at temperatures above 50°C.
• Serious infestations may require professionals to fumigate the house.