research on the epidemiological analysis of breed-related inherited diseases and harmful breed specifications of dog breeds in the Netherlands

Abstract

Breed-related disease and harmful breed specifications are a big problem in the global dog breeding sector, also in the Netherlands. It is clear that rigorous change in breeding is necessary in order to improve the long term well-being of purebred dogs. Only after identification and quantification of a breed’s health problems, further measures as modern DNA diagnostics and epidemiological techniques can be deployed to collectively and systematically develop new effective breeding policies. A primary need to effectively improve breed health, is that breeders have insight in the incidence of disease and of harmful breed characteristics in their breed population. The ‘Expertise Centre Genetics of Companion Animals’ (Faculty of Veterinary Medicine, Department of Clinical Sciences of Companion Animals of Utrecht University), that centers all scientific knowledge and research on veterinary genetics, population genetics and molecular genetics, aims to create this detailed insight in the status of breed-related health problems in the Netherlands. In the here reported research project, the progressive process is described of creating, thoroughly organizing and analyzing a disease registration database of dogs in the Netherlands. Qualitative analysis using existing literature, current veterinary expert opinions and the patient database of the University Clinic for Companion Animal Health of Utrecht University, gives insight in the health status of breeds. However, these data should be combined with quantitative data to draw reliable conclusions regarding the health of an entire breed population. Therefore, disease registrations from primary care veterinary practices were collected. These were automatically sent to and monitored in a standardized, cumulative and world-leading database showing diseases incidence in all breed populations. The aims of this Master thesis were (1) to set up a new standard for reporting qualitative analyses of diseases and harmful breed characteristics in Dutch purebred dog populations, and (2) to analyze recorded first line practice diagnostic data in the central database and develop an structured method to analyze these large scale data which could be used for future quick scan analysis of many populations. The database was thoroughly organized as such, that it generates a fast overview of the most problematic health issues for every breed. However, to indicate an overrepresentation of a breed within a disease, these data should be further analyzed. This can be done by comparing the incidence of a specific diagnosis, sub-diagnosis or involved organs system in breeds to this incidence in mixed-bred dogs. Another possibility is to use a method called data mining. This scientific analysis searches for statistical relations and/or patterns within a voluminous dataset. This method is time-consuming and complex, but prevents data exclusion and should therefore generate reliable results. As soon as data are accessible, these methods will indicate all overrepresentations in any breed, generating an evidence-based overview of the health status of breeds in the Netherlands. This project has resulted in a new format for standardized reporting of qualitative data of companion animal breed populations. Furthermore, a matrix for quantitative analysis of large scale first line diagnostic data was developed which may be employed for future quick scan data analysis. On the long term, this may contribute to new, evidence-based, breed-specific and durable breeding policies that improve and maintain the health of pedigree animals in the Netherlands.