There is growing evidence of environmental harm caused by veterinary medicines used to treat fleas and ticks. CAT graduate, Dr Julie Cayzer, a vet and zoologist, used her dissertation to design a workplace learning programme for vets to promote responsible use of these treatments.
The UK is facing a biodiversity crisis, with the latest State of Nature report describing us as one of the world’s most nature-depleted countries. A chance moment, hearing a lunchtime news article on the widespread damage to aqueous ecosystems caused by pet flea and tick products, decided my dissertation’s focus. I had been aware of the environmental harm caused by chemicals used to treat pets’ external parasites (fleas and ticks) and internal parasites (worms) for several years. The discussion on the radio focused on new evidence relating to two in particular – fipronil and imidacloprid (a neonicotinoid).
Balancing the health of animals, people and the environment
As a vet myself, I knew the statutory guidance given by the Royal College of Veterinary Surgeons and advice by leading national veterinary organisations was to avoid a blanket year-round approach to prescribing parasite treatments, and instead to tailor them for each pet and their human family. Something was preventing vets from responding to this new evidence of harm. Every vet values the natural world and wishes to protect it, yet we appeared to be unable to act on something so simple – to stop using the most harmful products and limit use of alternatives to a level that is deemed responsible.
Due to my background in veterinary education following years in clinical practice, I decided to co-create a training programme for UK vets on pet parasite treatments to promote their responsible use, drawing on the expertise and experiences of a wide range of veterinary experts and practitioners.
Crucially, the training would follow WHO’s One Health approach, aiming to sustainably balance and enhance the health of animals, people and the environment. This would allow greater flexibility to tailor prescribing behaviours to each individual context, thereby reducing the overall use of these drugs, and improving the outcomes for the environment without compromising public or animal health.
Influencing behaviour to achieve change
For my dissertation, I gathered expert insights from academic and practising veterinary professionals through interviews and focus groups. The codesign process involved four stages following the Design Council’s scheme to Discover, Define, Develop and Deliver the training programme. Throughout, I explored different components of behaviour that influence vets’ prescribing habits, following Susan Michie’s COM-B model. This model, which I had studied during the taught modules of my MSc at CAT, proposes that behaviour (B) is directed by the combined influences of capability (C), opportunity (O) and motivation (M). Twenty practising vets participated in the training prototypes, and our discussions revealed that motivation was key, with vets’ prescribing behaviour affected by social opportunity (practice team engagement) and time (to discuss treatment changes with owners).
It has been heartening to see a rapid response to the training programme by the vets involved in this research. Some have reported team discussions about moving away from spot-on treatments to potentially more environmentally friendly ones, for example, injectable products, so that less contaminated pet fur is shed. They have increased owner awareness regarding appropriate disposal (unwashed product packaging to landfill) and created tailored parasite treatments through lifestyle risk assessments. Empowered vets have begun to challenge systemic barriers such as automatic sign-ups to pet healthcare plans using year-round treatments where this was unnecessary following the pet’s risk assessment. Additionally, vets have reported engaging with further learning opportunities to find out more about the topic and to share this information with their practice teams.
The impact of learning at CAT
My dissertation at CAT gave me the opportunity to make a real difference; since submitting, I have continued to develop resources to enable the behaviour changes needed around responsible prescribing of these treatments by vets.
I volunteer with the Greener Veterinary Practice working group of Vet Sustain, a charitable organisation supporting veterinary sustainable actions across the profession. With them, I co-authored a peer-reviewed resource pack which included evidence-based medicine to support clinical decisions and lifestyle risk checkers to enable tailored parasite control regimes. The packs were released in September 2025 for vets and their teams to enable their responsible use of these treatments. Later that month, I presented my dissertation’s findings to the Vet Sustain curriculum team to explore their use by vet schools and the wider veterinary profession due to the current strategic importance of prevention of this pollution.
My training programme has also been piloted with local vets in the Hampstead Heath area. Joe Downie, a CAT classmate whose dissertation investigated pollution with these pesticides in the Heath’s ponds caused by swimming dogs, introduced me to an environmental researcher from the Heath and Hampstead Society, Jeff Waage (London Tropical School of Medicine). A new campaign by the Society to raise dog owners’ awareness of the pollution problem needed local vets’ support, so a joint event was held at Keats House on the Heath in October 2025 with two veterinary academic researchers (Rose Perkins, University of Sussex, and Andrew Prentis, Imperial College London) who raised the initial concerns about these pollutants. This event explored the behaviour changes by owners needed to protect local ecosystems and the role of advice from their vets. Follow-up online meetings with local vets to plan their support for the new campaign are ongoing.
As a vet, I fully understand the benefits to health and wellbeing from pet ownership. I have an elderly cat called Izzy – my life is enriched daily by her antics! Owners can make a significant difference in their environmental impact through everything from the choice of pet to care for, the food and kit that they buy, to the preventative measures that will keep them healthy. For advice on environmentally friendly choices, visit https://www.bva.co.uk/pet-owners-and-breeders/advice-for-pet-owners/how-can-i-reduce-my-pet-s-environmental-impact/.
Advice for pet owners
Please speak to your vet about a lifestyle risk assessment for your pet(s), as well as pet diseases caused by parasites. There are some that cause human disease, called zoonoses, that can be serious.
Follow their instructions on how and when to use the treatment and dispose of its packaging.
And:
- Bag and dispose of faeces in landfill.
- Do not allow your dogs to swim, be groomed or shampooed until at least one month after use of spot-on flea and tick treatments.
- Always read the product packaging to check what your pet parasite treatments contain. These two pesticides are commonly used in treatments sold outside of vet practices.
More information at bva.co.uk/petowners- and-breeders/advice-for-petowners/ parasite-treatments →
About the author
Julie completed her MSc in Sustainability and Behaviour Change at CAT in June 2025. Following a design route through her dissertation enabled her to collaborate with a wide range of experts in veterinary parasitology, as well as practising vets, to co-design a viable and relevant training programme. In her new role in the Royal College Veterinary Surgeons’ Knowledge team and at the University of Nottingham, Julie will continue to put the skills she gained at CAT into practice as she helps to shape the future of sustainable veterinary care.
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