Fleece-Lined Whelping Pools Associated with Reduced Incidence of Canine Hip Dysplasia in a Guide Dog Program

Using genetic selection, Guide Dogs for the Blind (GDB) has reduced the incidence rate of canine hip dysplasia (CHD). However, given that CHD is polygenic and multifactorial, environmental factors may impact the expression of this developmental condition. The objective of this original, correlational research was to investigate the relationship between the substrate in the whelping pool used from birth to 3 weeks of age and CHD diagnosis. This retrospective study included 5649 dogs (Labrador Retrievers, Golden Retrievers, and Labrador-Golden Retriever crosses) at GDB. A total of 2785 dogs were whelped between 1 July 2012 and 28 November 2015, when the whelping pools were lined with newspaper, and 2864 dogs were whelped between 5 March 2016 and 29 December 2019, when the whelping pools were lined with fleece. Bayesian regression modeling of the CHD diagnoses and PennHIP distraction index scores identified that dogs in the fleece group had a lower risk for CHD diagnosis but similar PennHIP scores compared to the newspaper group. Golden Retrievers had the highest risk of CHD diagnosis and PennHIP scores, followed by Labrador-Golden Retriever crosses and finally Labrador Retrievers, with the lowest risk of CHD diagnosis and PennHIP scores. No sex differences were identified for CHD diagnosis, but males had lower PennHIP scores than females. These results provide correlational evidence that housing-related environmental factors during the first three weeks of development-specifically, the substrate in the whelping pool-are associated with lifelong orthopedic health.