About the Rat Terrier
The Rat Terrier is an American breed developed from several breeds, see the ancestral tree below. Teddy Roosevelt kept them and is believed to have coined the breed name.
The American Kennel Club and the United Kennel Club - which are the two most reputable all-breed kennel clubs in the United States - recognize one breed, the Rat Terrier, with two varities, the Standard Rat Terrier and the Miniature Rat Terrier.
The Standard Rat Terrier is defined by both the AKC and the UKC as being over 13 inches (measured at point of the shoulder/withers) and up to and including 18 inches.
The Miniature Rat Terrier is defined by the AKC as being at least 10 inches, not to exceed 13 inches. The UKC has the same upper limit, but does not have a lower limit; even the smallest Rat Terrier is still a Miniture by the CKC breed standard. An AKC judge would probably describe a Rattie that was less than 10 inches as an undersized Rat Terrier.
The AKC says that any Rat Terrier over six months of age that is under 10 or over 18 inches is to be disqualified in the show ring; such dogs can still be registered with the AKC. The UKC is more lax only saying that over 19 inches is a fault.
The Rat Terrier was recognized by the United Kennel Club on January 1, 1999. The UKC Rat Terrier page is here.
The Rat Terrier Club of America "RTCA" is the parent club for the Rat Terrier with the American Kennel Club "AKC". The breed was fully accepted into the AKC on June 1, 2013. The AKC Rat Terrier page is here.
The Decker Rat Terrier is just a particular line of Rat Terrier which has been selected for increased size and to be a hunting dog. The Decker is also known as the Old Dominion Terrier, by those seeking to establish it as a seperate breed.
Short-bodied long-legged and long-bodied short-legged dogs used to be interbred and referred to as Type A and Type B Rat Terriers, respectively. However, Type B has been broken off into a seperate breed, the Teddy Roosevelt Terrier. The terms Type A and Type B Rat Terrier should no longer be used. The American Hairless Terrier is another breed developed entirely from the Rat Terrier.
The Toy Rat Terrier can be just a small Rat Terrier, generally defined as under 10 inches, but it can also be a mix between Rat Terriers and Toy Fox Terrers and/or Chihuahuas. Be especially alert to the mixed-breed possibility if a Toy is not UKC or AKC registered, but instead are only registered with one of the less reputable registries. The UKCI (Universal Kennel Club), CKCI (Contentenental Kennel Club Inc) (WARNING: sometimes incorrectly referred to as CKC, a term which should be reserved for the highly reputable Canadian Kennel Club) and NRTA (National Rat Terrier, Association) do recognize the Toy Rat Terrier.
The American Kennel Club and the United Kennel Club - which are the two most reputable all-breed kennel clubs in the United States - recognize one breed, the Rat Terrier, with two varities, the Standard Rat Terrier and the Miniature Rat Terrier.
The Standard Rat Terrier is defined by both the AKC and the UKC as being over 13 inches (measured at point of the shoulder/withers) and up to and including 18 inches.
The Miniature Rat Terrier is defined by the AKC as being at least 10 inches, not to exceed 13 inches. The UKC has the same upper limit, but does not have a lower limit; even the smallest Rat Terrier is still a Miniture by the CKC breed standard. An AKC judge would probably describe a Rattie that was less than 10 inches as an undersized Rat Terrier.
The AKC says that any Rat Terrier over six months of age that is under 10 or over 18 inches is to be disqualified in the show ring; such dogs can still be registered with the AKC. The UKC is more lax only saying that over 19 inches is a fault.
The Rat Terrier was recognized by the United Kennel Club on January 1, 1999. The UKC Rat Terrier page is here.
The Rat Terrier Club of America "RTCA" is the parent club for the Rat Terrier with the American Kennel Club "AKC". The breed was fully accepted into the AKC on June 1, 2013. The AKC Rat Terrier page is here.
The Decker Rat Terrier is just a particular line of Rat Terrier which has been selected for increased size and to be a hunting dog. The Decker is also known as the Old Dominion Terrier, by those seeking to establish it as a seperate breed.
Short-bodied long-legged and long-bodied short-legged dogs used to be interbred and referred to as Type A and Type B Rat Terriers, respectively. However, Type B has been broken off into a seperate breed, the Teddy Roosevelt Terrier. The terms Type A and Type B Rat Terrier should no longer be used. The American Hairless Terrier is another breed developed entirely from the Rat Terrier.
The Toy Rat Terrier can be just a small Rat Terrier, generally defined as under 10 inches, but it can also be a mix between Rat Terriers and Toy Fox Terrers and/or Chihuahuas. Be especially alert to the mixed-breed possibility if a Toy is not UKC or AKC registered, but instead are only registered with one of the less reputable registries. The UKCI (Universal Kennel Club), CKCI (Contentenental Kennel Club Inc) (WARNING: sometimes incorrectly referred to as CKC, a term which should be reserved for the highly reputable Canadian Kennel Club) and NRTA (National Rat Terrier, Association) do recognize the Toy Rat Terrier.
Above: AKC Gazette, November 2019, pages 64 & 65.
Above is the Rat Terrier ancestry tree that used to be on the RTCA website. Below is the tree that is currently (25 Apr 2022) on the RTCA website.