The development of a dog breed often involves selection, which intentionally propagates valued genetic traits. Unfortunately, untoward traits can be collaterally propagated during this process. For the purpose of identifying trends in canine genetic diseases, we examined 36 randomly chosen canine pathologies involving single gene mutations. For each disease we provide a brief summary of breed predilection, clinical signs, the underlying genetic mutation, and the availability of a commercial diagnostic test. The following trends were noted in this non-exhaustive list of diseases. First, these genetic diseases primarily involve the ophthalmic (28%) and nervous systems (28%). Second, no single breed was over-represented in these genetic diseases. Third, the majority (89%) of the mutations involve coding regions of the respective genes. Fourth, most (78%) mutations were autosomal recessive. Fifth, nucleotide substitutions were the most common mutation (42%). Finally, genetic testing is available for 89% of these diseases. This review encapsulates canine pathologies associated with single genetic defects, thus providing a resource for practitioners and researchers.