The Garrano takes its name from Celtic linguistic roots, with "garrano" derived from "gher" or "gerran" meaning "small horse" in ancient Celtic languages. This etymology connects the breed to the Celtic peoples who likely introduced similar ponies to the Iberian Peninsula during migrations approximately three thousand years ago. The breed is also known as Minho, Garrano do Minho, and Trás os Montes, referencing the northern Portuguese regions where it has survived for millennia.
The official breed registry is the Associação de Criadores de Equinos da Raça Garrana, known by its acronym ACERG. Formed within the farmers' cooperative of Vieira do Minho in 1988, the association became independent in 1990 and received official Portuguese government approval in 1995. The breed standard was formally established in 1993, creating consistent criteria for registration and breeding programs.
ACERG maintains a genealogical registry divided into the Birth Book for young animals and the Adult Book for breeding stock. The organization oversees conservation efforts for this endangered breed, including animal identification through microchips and brands, genetic testing to ensure purity, and coordination of breeding programs designed to maintain genetic diversity while meeting breed standards. By 2024, the registry included over 2,550 breeding mares, though fewer than 1,700 were classified as pure-bred, reflecting ongoing work to distinguish purebred populations from crossbred individuals.
