The British Small Animal Veterinary Association (BSAVA) recommends that companion animals are treated for parasites, both internal (e.g. worms) and external (e.g. fleas, ticks, mites), taking into consideration individual circumstances. These treatments are recommended because they promote good animal health and welfare and, in the case of zoonotic infections, help to minimise risk to human health.

The BSAVA also recommends that appropriate hygiene measures are taken (e.g. removal of faeces from the environment and hand washing) in order to reduce the risk of parasite infection. In some circumstances, the animal’s indoor living environment may also need to be treated to reduce parasite burden.

The BSAVA recommends that owners should consult their veterinary surgeon to discuss the appropriate prevention and treatment for individual animals.

The BSAVA strongly supports further scientific research into the epidemiology, control and prevention of parasitic infections of companion animals (in particular those with zoonotic potential), and publication of such research so as to provide veterinary surgeons with appropriate information on which to base decisions.

The BSAVA recommends that veterinary surgeons take into consideration the potential adverse impact of parasiticides on the environment when considering health care plans for individual animals and minimise the impact where possible.

Date January 2022

Background information

A thorough risk-benefit assessment should be undertaken on an individual case-by-case basis, including consideration of lifestyle and occurrence/distribution of parasites locally. Treatment can then be selected based on the required spectrum of activity, method and frequency of administration and likely owner compliance. Particular attention should be given to the treatment of young animals. In cases of high risk or where there is increased zoonotic potential, maximising control according to the manufacturer’s recommendation is advised. In other cases, the risk of infection may be so low as to recommend intermittent anti-parasite treatment. It is also very important to consider the potential for contamination of the environment by anti-parasite medication, especially the potential contamination of water courses with topically applied treatments.

If travelling abroad with an animal, or bringing an animal into the UK from abroad, owners should ensure that they check the relevant government website that the animal is travelling to and from to ensure that they comply with relevant legislation. This will also minimise the introduction of new parasites, parasitic diseases and other diseases transmitted by parasites, to the UK. The BSAVA recommends treatment for both tapeworms and ticks before re-entry to the UK.

Further information

NOAH: Companion Animal Parasite Control
BSAVA Scientific Information Document: Babesia canis
BSAVA Scientific Information Document: Lyme disease
BVA, BSAVA and BVZS policy position on responsible use of parasiticide veterinary medicinal products used in companion animals
EMA: Environmental risk assessment for parasiticide veterinary medicinal products used in companion animals


Reviewed by members of BSAVA Scientific Committee (Alexander German, Jeremy Kirk, Caroline Kisielewicz, Lisa Morrow, Ian Self, Melissa Upjohn and James Warland) 2022

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