| Country of origin: | USA |
| Registries: | AKC FSS, UKC, Rat Terrier Club of America, National Rat Terrier Association |
| Occupation: | Vermin hunter, companion |
| Size: | 2–3kg (4–7lb), 25cm (10in) |
| Longevity: | 14 to 16 years |
| Exercise: | Vigorous daily exercise |
| Training: | Challenge |
| Grooming: | Easy |
| Colors: | Black and white, tan and white, tricolour |
The breeders who developed the American Toy Terrier miniaturized its body, but not its personality. Also called the Toy Fox Terrier or Amertoy, this breed shows the influence of Chihuahuas and English Toy Terriers in its domed head and erect ears, but that of the Smooth Fox Terrier in its nature. These busy, querulous dogs were bred in the 1930s for their ratting ability. Today, they are family companions suited to both urban and rural life, and with patient training have proved natural and obedient guard dogs and sentinels.