Mutant allele frequencies among domestic cats in some eastern areas of Canada: regional homogeneity of factors in Canadian Atlantic Provinces and the French colony of Saint Pierre.

Surveys to determine mutant allele frequencies in domestic cats of the Canadian Atlantic Provinces (Halifax, Nova Scotia; Fredericton, New Brunswick; Charlottetown, Prince Edward Island; St. John's Newfoundland) and the French colony of Saint Pierre, Saint Pierre et Miquelon, reveal a general regional homogeneity for most factors. Despite diverse historical patterns of settlement, a strong common component of origin is indicated. This is tentatively identified as late 18th and early 19th century British. One mutant, polydactyly, which is of New England origin appears to have been distributed largely by loyalist refugees from New England at the time of the American Rebellion. No elements of a specific Acadian (French) character have yet been identified. Siamese cats have been "introduced" to the region in recent years and are now so abundant that they will undoubtedly cause a significant change in some mutant allele frequencies over the next few decades. Interregional exchanges of cats no doubt are contributing to homogenizing the populations of the area, but the practice of sterilization of pets offsets this to some degree.