Leptospirosis vaccination in dogs attending UK primary care practices: vaccine uptake and factors associated with administration.

Background: Leptospirosis is a zoonotic disease that is found globally and affects most mammalian species. Vaccination of dogs against leptospirosis is an important approach to preventing clinical disease, or reducing disease severity, as well as reducing transmission of the infection to humans. Although it is generally considered to be a 'core' vaccine, there is limited information on the level of leptospirosis vaccine usage and factors associated with its usage in dogs in the UK. The study aimed to report the uptake of leptospirosis vaccination and factors associated with its usage in a cohort of dogs under primary veterinary care during a 12-month period.

Results: From a population of 905,543 dogs, 49% (95%CI 48.9-49.1%) had at least one leptospirosis vaccine administered during the 12 months of study. Adult dogs had reduced odds of receiving a leptospirosis vaccine when compared to dogs < 1 year old, with dogs > 8 years old having a greater than ten-fold reduction in odds (OR = 0.08, 95%CI 0.07-0.09). Odds of receiving a leptospirosis vaccine was increased in insured dogs when compared to uninsured dogs (OR = 1.22, 95%CI = 1.17-1.28). Neutered dogs had reduced odds of receiving a leptospirosis vaccine (OR = 0.87, 95%CI 0.83-0.91). Breed associations with receiving a leptospirosis vaccine varied. Several breeds were associated with increased odds of receiving a leptospirosis vaccine when compared to crossbreed dogs, including Border Terriers (OR = 1.49, 95%CI 1.42-1.57), Golden Retrievers (OR = 1.30, 95%CI = 1.24-1.37), Cocker Spaniels (OR = 1.27, 95%CI 1.23-1.31) and West Highland White Terriers (OR = 1.27, 95%CI 1.22-1.31). French Bulldogs (OR = 0.64, 95%CI = 0.62-0.67), Staffordshire Bull Terriers (OR = 0.79, 95%CI 0.78-0.82) and Pugs (OR = 0.91, 95%CI =0.88-0.95) had significantly reduced odds of receiving a leptospirosis vaccination during the study.

Conclusion: This work identified that almost half of the UK primary care attending population received a leptospirosis vaccine during the year. Several demographic variables were associated with leptospirosis vaccine administration, with age being particularly important. Both the proportion of uptake and factors associated with leptospirosis vaccine usage can be used as a benchmark for comparisons in the future. Additionally, an understanding of which populations have reduced odds of receiving a leptospirosis vaccine can potentially be used for initiatives to encourage owner vaccination uptake in these groups.