Our policies

Responsible use of parasiticides for cats and dogs

What’s the issue?

Parasiticide products are commonly used in small animal medicine to prevent and treat for various parasites, including fleas, ticks and worms. As well as preventing animal health and welfare problems, human health risks from associated zoonotic threats have to be considered.

There is increasing concern that some of these medicines are contaminating the environment, potentially reaching rivers through wastewater. With more and more people owning pets, and many of them being regularly treated for parasites, the volume of products being used has increased. As parasiticides are harmful to a wide range of invertebrates, and with even small doses potentially impacting large numbers, this could be highly detrimental to wildlife and ecosystems and, in turn, public health.

In the farm animal and equine sectors, there are concerns over high levels of resistance to parasiticide products as a result of misuse and overuse. Whilst this is not currently an evidenced threat in small animal medicine, it could become an issue and maintaining the efficacy of these products in the future is important.

This is a true One-Health problem of immense complexity, with potential conflict between the needs of animal health, human health, and the health of the wider ecosystem.

What’s our view?

Concerns about the possible environmental impacts of small animal parasiticide products should be taken seriously by the veterinary profession, pharmaceutical industry, and animal owners

Veterinary professionals should always take a risk-based approach to prescribing medicines, including parasiticides. They should avoid blanket treatment, and instead risk assess use of parasiticides for individual animals, taking into account animal, human and environmental health risks, in addition to lifestyle factors.

However, there are many knowledge gaps in relation to parasites and the use of parasiticide products, making that risk analysis difficult. Our position highlights these gaps and calls for more research to be undertaken in a number of areas, including:


  • the factors which could increase the risks of pets being infected by parasites, eg seasonality
  • the impacts and prevalence of parasite-borne disease on human health
  • the impacts of parasiticides on non-target invertebrates
  • the source, prevalence and impacts of veterinary parasiticide products in the natural environment
  • how companion animal parasiticide products are bought, used, and disposed of
  • the threat posed by resistance to common companion animal parasiticides
  • the optimal use of parasiticide products, eg required frequency of application
  • non-chemical methods of parasite prevention

Our understanding and position will develop as the evidence base grows.

Improper use of products can increase the risk of environmental contamination, so education is important. Veterinary professionals can help to promote clear information to the animal owning public, and veterinary organisations, such as BVA, should proactively promote discussion and highlight concerns. Everyone has a role to play to encourage responsible prescribing, and to develop guidance to support making responsible choices.

The VMD and pharmaceutical industry also have a responsibility to consider how medicines are promoted and distributed, including:

  • reviewing the requirements for environmental impact assessments of companion animal products
  • reconsidering the classification of parasiticides which are available without professional advice
  • collecting, monitoring, and publishing sales data, to aid research and understanding
  • improving information provided with veterinary medicines, so key points on safe usage are clearly and simply presented


The small animal sector as a whole needs to acknowledge the challenges and work together to consider what constitutes responsible use of parasiticides. In our position, we make a total of 37 recommendations, aimed at a range of stakeholders, to help progress the conversation. 


Client resource pack

We've developed a resource pack to help you speak to your clients about how to responsibly use parasiticides for dogs and cats, ensuring any negative impacts to pets, people and the planet are minimised.

Download our:

  • Posters
  • Leaflet
  • Practice screen slides

To download our practice screen slides in mp4 format, please contact [email protected].

Download resource pack
Resources Image

Five point plan poster

We're urging veterinary professionals to always take a risk-based approach to prescribing parasiticides. It's important to consider the risks to animal, human, and environmental health. 

Our five-point plan poster has been developed in collaboration with BSAVA and BVZS to support veterinary professionals in decision making around the use of parasiticides. 

Download our poster

Get involved

Contact our policy team for more information