UntitledThe frequency, risk factors and spatial distribution associated with the diagnosis of leishmaniasis in dogs in the UK in 2019

BackgroundLeishmaniosis in dogs is an important zoonotic disease, endemic in southern Europebut is increasingly being recorded in other parts of Europe including the UK. Thisstudy aimed to update the epidemiological knowledge of leishmaniosis in the UK dogpopulation.MethodsThe estimated prevalence of leishmaniosis diagnosis in dogs under care at VetCompassUK participating practices in 2019 was calculated. Risk factor associations forleishmaniosis were investigated using mixed-effects multivariable logistic regressionmodelling. The spatial distribution of leishmaniosis was explored using standardisedmorbidity rates (SMR) at regional and county levels, and Moran’s I was used to identifysignificant spatial autocorrelation.ResultsThe estimated annual prevalence was calculated as 0.0434% (95% CI 0.0427–0.0443) with 976 cases from this population of dogs (n = 2,250,741). Most of the dogswith leishmaniosis had originated from outside the UK (955/976, 97.9%) and of those,60.8% (581) had already been diagnosed with leishmaniosis pre-import. In the riskfactor analysis, the odds of leishmaniosis were higher in males (OR 1.29, 95% CI1.12–1.49) and neutered dogs (OR 6.42, 95% CI 4.43–9.29) compared to female andentire dogs, respectively. Purebreds overall had lower odds of leishmaniosis comparedto crossbreeds (OR 0.24, 95% CI 0.20–0.28) but there were specific breedssuch as Brittany Spaniels (OR 53.0, 95% CI 25.3–111.1), Ibizan Hounds (OR 43.8,95% CI 9.20–208.3) and English Pointers (OR 28.6, 95% CI 14.5–56.4) which hadmuch higher odds of being a case compared to crossbreeds. Spatial analysis identified more leishmaniosis cases in southern England than were expected by random chance (SMR > 1).ConclusionsThis study identifies that imported animals are the commonest source of dogs having a leishmaniosis diagnosis. The breeds with very high odds for leishmaniosis may reflect selection bias towards breeds more likely to be imported, rescued or travelled from endemic areas rather than high intrinsic risk in these breeds towards leishmaniosis. These results support and update previous studies indicating that most cases are diagnosed in southern England.