Canine atopic dermatitis: breed risk in Australia and evidence for a susceptible clade

Abstract

BackgroundGenetic studies on canine atopic dermatitis (CAD) indicate that large populations from one geographical location are preferred for the identification of relevant susceptibility genes. Australian dogs are relatively isolated; studies onCADin this population are limited.Hypothesis/ObjectivesTo identify breeds at risk in the Australian dog population and to compare with worldwide breed predisposition.AnimalsCase records (n = 23,000) from University Veterinary Teaching Hospital (UVTH) dogs, including 722 withCAD.MethodsThe breed proportion ofCADand odds risk (OR) were calculated. A systematic review of 13 previous studies (1971–2010) was performed and compared to the study results by implementing an atopic dermatitis (AD)‐to‐reference population ratio (ADRPR).ResultsEleven dog breeds with significant increasedOR(≥1.0) were identified; all with breedCADcases proportionally higher than their base hospital population. Gender risk in males from the pug dog breed (P = 0.007) was detected and the bichon frise breed had a similar trend (P = 0.05). Sixteen predisposed dog breeds were identified by systematic review. All breeds with significant increasedORinUVTHhadADRPR > 1.4; five (boxer, bulldog, Labrador retriever, pug, West Highland white terrier) were recognized as predisposed worldwide. One clade of breeds with common ancestry was highly represented inCADcases worldwide and in Australia (81% of the significantORcases).Conclusion and clinical importanceThe use of a large population from one geographical location andADRPRprovided an objective comparison between worldwideADstudies; it identified one common clade of susceptible breeds. Breed genetics and related clinical presentation may helpCADdiagnosis and treatment.