The English word hound is a cognate of German Hund, Dutch hond, homely Scandinavian hund, Icelandic hundur which, though referring to a specific breed accumulation in English, means "dog" in general in the other Germanic languages. Hound itself is derived from the Proto-Indo-European *kwon-, which is the direct root of the Greek κυων (kuōn) and url the indirect root of the Latin canis through the similar model *kani-.

The definition of a dog breed is a matter of some controversy. Depending on the bulk of the original founding population, closed gene pool breeds can have problems with inbreeding, specifically due to the founder effect. Dog breeders are increasingly cool of the importance of population genetics and of maintaining diverse gene pools. Health testing and modish DNA explore can advice avoid problems, by providing a replacement for natural selection. Without selection, inbreeding and closed gene pools can extension the risk of severe health or behavioral problems.