Canine coat color is a readily observed phenotype of great interest to dog enthusiasts; it is also an excellent avenue to explore the mechanisms of genetics and inheritance. As such, multiple commercial testing laboratories include basic color alleles in their popular screening panels, allowing for the creation of genotyped datasets at a scale not before appreciated in canine genetic research. These vast datasets have revealed rare genotype anomalies that encourage further exploration of color and pattern inheritance. We previously reported the simultaneous presence of greater than two allele variants at the Agouti Signaling Protein (ASIP) locus in a commercial genotype cohort of 11,790 canids. Here we present additional data to characterize the occurrence of anomalous ASIP genotypes. We document the detection of combinations of three or four ASIP allele variants in 17 dog breeds and Dingoes, at within-breed frequencies of 1.32–63.34%. We analyze the potential impact on phenotype that these allele combinations present, and propose mechanisms that could account for the findings, including: gene recombination, duplication, and incorrect causal variant identification. These findings speak to the accuracy of industry-wide protocols for commercial ASIP genotyping and imply that ASIP should be analyzed via haplotype, rather than using only the existing allele hierarchy, in the future.

The factor VII (FVII) protein is an integral component of the extrinsic coagulation pathway. Deleterious variants in the gene encoding this protein can result in factor VII deficiency (FVIID), a bleeding disorder characterized by abnormal (slowed) clotting with a wide range of severity, from asymptomatic to life-threatening. In canids, a single FVIID-associated variant, first described in Beagles, has been observed in 24 breeds and mixed-breed dogs. Because this variant is present in breeds of diverse backgrounds, we hypothesized that it could be a contributing factor to unexplained bleeding observed in some canine autopsy cases. DNA was extracted from paraffin-embedded tissue samples from 67 anticoagulant-negative autopsy cases with unexplained etiology for gross lesions of hemorrhage. Each dog was genotyped for the c.407G>A ( F71) variant. Experimental controls included 3 known heterozygotes and 2 known homozygotes for the F71 variant, 2 normal dogs with known homozygous wild-type genotypes ( F7W F7W), and 5 dogs with bleeding at autopsy that tested positive for anticoagulant rodenticide and were genotyped as F7W F7W. All 67 cases tested homozygous for the wild-type allele, indicating that the common FVIID variant was not responsible for the observed unexplained bleeding. Our work demonstrates the usefulness of retrospective studies utilizing veterinary diagnostic laboratory databases and tissue archives for genetic studies. In the case of FVIID, our results suggest that a singular molecular test for the F71 variant is not a high-yield addition to postmortem screening in these scenarios.