Summary of current knowledge of the size and spatial distribution of the horse population within Great Britain

Abstract

BackgroundRobust demographic information is important to understanding the risk of introduction and spread of exotic diseases as well as the development of effective disease control strategies, but is often based on datasets collected for other purposes. Thus, it is important to validate, or at least cross-reference these datasets to other sources to assess whether they are being used appropriately. The aim of this study was to use horse location data collected from different contributing industry sectors ("Stakeholder horse data") to calibrate the spatial distribution of horses as indicated by owner locations registered in the National Equine Database (the NED).ResultsA conservative estimate for the accurately geo-located NED horse population within GB is approximately 840,000 horses. This is likely to be an underestimate because of the exclusion of horses due to age or location criteria. In both datasets, horse density was higher in England and Wales than in Scotland. The high density of horses located in urban areas as indicated in the NED is consistent with previous reports indicating that owner location cannot always be viewed as a direct substitute for horse location. Otherwise, at a regional resolution, there are few differences between the datasets. There are inevitable biases in the stakeholder data, and leisure horses that are unaffiliated to major stakeholders are not included in these data. Despite this, the similarity in distributions of these datasets is re-assuring, suggesting that there are few regional biases in the NED.ConclusionsOur analyses suggest that stakeholder data could be used to monitor possible changes in horse demographics. Given such changes in horse demographics and the advantages of stakeholder data (which include annual updates and accurate horse location), it may be appropriate to use these data for future disease modelling in conjunction with, if not in place of the NED.

Where are the horses? With the sheep or cows? Uncertain host location, vector-feeding preferences and the risk of African horse sickness transmission in Great Britain

“…Previous studies have shown that the distribution of NED-registered horse owners does not mirror the distribution of locations where the corresponding registered horses are kept [8,19,20]. We showed that mapping owner addresses as a simple proxy for horse location underestimates the risk of an outbreak of AHS in GB.…”

“…Previous studies [8,19,20] have shown that the distribution of NED-registered horse owners does not mirror the distribution of locations where the corresponding horses are kept. In particular, a survey of NED-registered owners (1009 samples) provided complete postcode records for owners and their corresponding horse locations [19], and revealed an inverse relationship between built-up land use and the proportion of horses kept at the same postcode as owners' addresses [8].…”

Demographics of Australian horse owners: results from an internet‐based survey

“…There have been surveys of horse owners to determine demographic parameters in overseas countries using a variety of methods . The results are consistent globally, including in Australia , independent of the survey method, the year(s) the study was undertaken and the country or region where the study was conducted.…”

The accuracy of the National Equine Database in relation to vector‐borne disease risk modelling of horses in Great Britain

“…Inaccurate data for the numbers and distribution of horses and their proximity to other hosts might lead to erroneous associations with localised parameters resulting in incorrect estimates of the magnitude of R 0 and not simply a spatial redistribution of its values. Estimates on the size of the horse population have ranged from 840,000 to 1.2 million horses, based on various different sampling methods, such as telephone surveys and using data from equine organisations such as charities as well as agricultural census data from the Department for Environment Food and Rural Affairs (DEFRA) and the National Equine Database (NED), which collates horse passport data . It is plausible that NED should contain the most accurate data on the horse population as it is a legal requirement for all horses in the UK to have a passport and data from passports are centrally stored on NED.…”