Exploring vaccination uptake trends in UK companion animals

6 January 2023

Professor Gina Pinchbeck, at the University of Liverpool, received partial funding from BSAVA PetSavers for a PhD entitled A mixed methods approach to quantifying and characterising vaccine uptake and vaccine hesitancy in UK companion animals. PhD student Shona Bloodworth describes the background to, and initial findings of, the study.

For most dog and cat owners, a reminder letter prompting a visit to their veterinary surgery for a health check and booster is anticipated each year. The vaccination card is dug out and an appointment for vaccinations and health check is booked. Vaccinations have formed an important component of preventative care for companion animals since their introduction in the 1970s. This approach has been highly successful, reducing incidence of some of the most important infections in cat and dog populations. However, the PDSA Paw report of 2019 suggested that vaccination uptake in the cat and dog population had dwindled. The extent of any such decline, and the reasons that impact an owner’s choice to have their pet vaccinated are not well understood.

A Google or Facebook search can quickly lead to websites and groups that point to a growing movement of vaccine hesitancy in the companion animal sector, particularly amongst dog owners. Emotive reports that direct public attention to rare incidences of adverse events following vaccinations; perceptions of disease risk; and the apparent increase in popularity of the pursuit of ‘natural’ lifestyles and remedies for pets might be speculated as reasons for increasing vaccine hesitancy amongst pet owners. However, it is also possible that the decision of some owners to not vaccinate may be linked to cost, difficulty accessing a veterinary surgery, or lack of awareness of the need to vaccinate. We know that hesitancy towards vaccinations for humans is context-dependent, and factors that influence vaccine hesitancy include complacency, convenience and confidence. It is likely that the factors that influence humans to be hesitant in having themselves vaccinated might also be applicable when it comes to having their pets vaccinated too.

It is against this background that BSAVA PetSavers approved funding for a PhD that seeks to understand better the current trends in vaccination uptake in the UK pet population. This is a prerequisite to ensuring as many as possible of the dogs and cats in the UK get the right vaccines at the right time for their lifestyle. This unique study uses quantitative analysis of large volumes of electronic health records of cats and dogs from across the UK to estimate uptake and trends in vaccination. This ‘big data’ approach is being complemented by a qualitative analysis of in-depth interviews with pet owners and small animal veterinary surgeons.

Using data from the Small Animal Surveillance Network (SAVSNET), we estimate that of the 659,408 dogs and 311,135 cats in the database, 80% of dogs and 73% of cats have a record of at least one vaccination in their lifetime. Models produced from the data show that for both cats and dogs, those that are neutered are more likely to have a record of vaccination when compared to entire animals. The growing trend for the raw feeding of dogs, allied with increased discussion on special interest pages about raw feeding suggesting some owners choosing this feeding method may be more inclined to be vaccine hesitant, prompted us to look for evidence of any links between vaccination and raw feeding in the SAVSNET data. Vaccination data for both raw fed dogs and control non-raw fed dogs showed that 85% of dogs where there was no evidence of a raw diet received at least one vaccination in their lifetime, compared to 81% of raw fed dogs. This was a consistent pattern, with a higher proportion of control dogs receiving core vaccinations and vaccinations for leptospirosis, kennel cough (Bordetella bronchiseptica) and canine parainfluenza. We now need to understand the reasons for these differences.

The next phase of this project involves interviewing dog and cat owners about their experience and attitude to vaccinating their pets, as well as exploring their approach to general care and the relationships they have with their animals. Based on analysis of the SAVSNET data, we were also able to show that pets of owners living in areas with high deprivation scores are less likely to be vaccinated. This suggests that for some owners, cost could be a barrier to getting their animal vaccinated. However, other socioeconomic metrics that are used to calculate deprivation scores, such as levels of education, skills and training deprivation, and barriers to services, may also be contributing factors. Interviews with owners from more deprived backgrounds will improve our understanding of the factors that influence their approach to vaccination for their pets. An ongoing challenge is to recruit participants for interview that will help us to answer the questions that have arisen from the quantitative data analysis.

It is hoped that the findings of this research will be used to develop strategies that will help owners get their pets vaccinated the appropriate number of times for its particular age and lifestyle. Focus groups with veterinary professionals and owners will be held to discuss the feasibility and acceptability of any proposed actions, and ultimately help to decide on the best process going forward.

This project has offered me the opportunity to develop my skills as a researcher. My fantastic supervisory team has supported me in learning how to manage and analyse big data and to undertake and analyse interviews. We are hugely grateful to PetSavers for funding this work, without which this kind of research is very hard to do.