Among Indigenous populations of the Arctic, domestic dogs (Canislupus familiaris) were social actors aiding in traction and subsistence activities. Less commonly, dogs fulfilled a fur-bearing role in both the North American and Siberian Arctic. Examples of garments featuring dog skins were collected during the 19th-20th centuries and are now curated by the National Museum of Denmark. We sequenced the mitochondrial genomes of macroscopically identified dog skin garments. We conducted stable carbon and nitrogen isotope ratio analysis of the dog furs and of fur samples from contemporaneous pelts of Arctic (C. lupus arctos) and grey (C. lupus) wolves. Despite the presence of biocides used to protect the fur clothing during storage, we extracted well-preserved DNA using a minimally-invasive sampling protocol. Unexpectedly, the mtDNA genomes of one-third of the samples were consistent with wild taxa, rather than domestic dogs. The strong marine component in the diets of North American dogs distinguished them from Greenland and Canadian wolves, but Siberian dogs consumed diets that were isotopically similar to wild species. We found that dog provisioning practices were variable across the Siberian and North American Arctic, but in all cases, involved considerable human labor.