Despite identifying some shared gene associations with human atopic dermatitis the use of multiple dog breeds from various locations limits detection of gene associations in canine atopic dermatitis

Canine atopic dermatitis (cAD) is a common, severe pruritic and inflammatory skin disease and is a major veterinary welfare issue. This study genotyped 97 single nucleotide polymorphisms (SNPs) in 25 candidate genes in 659 dogs across eight breeds from three locations (UK, USA and Japan). These genes were selected from hAD literature, and previous cAD gene expression experiments. The aim of this study was to identify any shared gene associations between cAD and hAD.Only one SNP within the TSLP-receptor was associated with all eight breeds (corrected p = 0.037). Five SNPs within Filaggrin, DPP4, MS4A2, and INPPL1 were associated with cAD, but only in certain breeds from different locations. Though these associations are broadly similar to hAD the variability of results across the breeds and locations demonstrates that a candidate gene approach using mixed breeds from different locations is not appropriate. This study therefore suggests that further candidate gene studies in cAD should be breed and location specific to increase the likelihood of finding associations with the disease.