It is very unlikely that the dog will develop Progressive Retinal Atrophy (rcd3 PRA) but since it carries the mutant gene, it can pass it on to its offspring with the probability of 50%.Ĭarriers should only be bred to clear dogs.Īvoid breeding carrier to carrier because 25% of their offspring is expected to be affected (see table above) The dog carries one copy of the mutant gene and one The dog will never pass the mutation to its offspring, and therefore it can be bred to any other dog. It is very unlikely that the dog will develop Progressive Retinal Atrophy (rcd3 PRA).
The dog is noncarrier of the mutant gene. Phenotypic Effects of FGF4 on IVDD (2019) In some breeds both mutations are present and so breeders will be able to plan breeding to reduce occurrence of CDDY, while retaining the short-legged phenotype CDPA.įGF4 retrogene on CFA12 is responsible for CDDY and IVDD CDPA inheritance is considered to follow am autosomal dominant mode. The second mutation CDPA explains the short-legged phenotype known as chondrodysplasia (CDPA) in breeds such as Basset Hound, Pembroke Welsh Corgi, Dachshunds, West Highland White Terriers and Scottish Terriers. The CDDY mutation has been found in breeds such as: Basset Hound, Beagle, Bichon Frise, Cardigan Welsh Corgi, Cavalier King Charles Spaniel, Chesapeake Bay Retriever, Chihuahua, American Cocker Spaniel, Coton de Tulear, Dachshund, Dandie Dinmont Terrier, English Springer Spaniel, French Bulldog, Havanese, Jack Russell Terrier, Nova Scotia Duck Tolling Retriever, Pekingese, Pembroke Welsh Corgi, Poodle (Miniature and Toy), Portuguese Water Dog, Scottish Terrier, Shih Tzu. As for IVDD, the inheritance follows a dominant mode, meaning that 1 copy of CDDY mutation is sufficient to predispose dogs to IVDD. CDDY is inherited as a semi-dominant trait which means that dogs with 2 copies of the mutation are smaller than dogs with only 1 copy. These abnormal discs are susceptible to herniation into the spinal canal where the inflammation, and hemorrhage can cause severe pain and neurological dysfunction. In affected dogs, premature calcification of part of the disc at early age (from birth to 1 year of age) results in degeneration of all discs in young dogs. The intervertebral disc lie between the vertebrae and it is made of a cartilage which separate vertebrae from each other, absorb shocks and allow slight movement of the vertebrae. CDDY can also be associated with Intervertebral Disc Disease (IVDD) due to premature degeneration of the intervertbral disc. The test checks for two mutations: CDDY with IVDD Risk, and CDPA.Ĭhondrodystrophy CDDY (FGF4-12) which causes short legs and the risk of developing Intervertebral Disc Disease (IVDD).Ĭhondrodysplasia CDPA (FGF4-18), which causes the short legged phenotype in a number of breeds.Ĭhondrodystrophy (CDDY with IVDD Risk) is a trait that is common to many dog breeds and it is characterised by shorter legs due to shorter long bones.
Research found that there is no association between the bobtail mutation and the short tail phenotype in the following breeds: Boston Terrier, English Bulldog, King Charles Spaniel, Miniature Schnauzer, Parson Russell Terrier, Rottweiler.Ĭhondrodystrophy (CDDY with IVDD Risk) and Chondrodysplasia (CDPA) Homozygous for the mutation (T/T): does not exist and thought to be lethal. Heterozygous dogs can pass the mutation to their offspring with a probability of 50%. Heterozygous (N/T): The dog carries one copy of the normal gene and one copy of the mutant gene the dog has a natural short tail. Normal (N/N): The dog has two copies of the normal gene and will have a normal tail. The test does not differentiate between tailless and stumpy tail Please note that the Short tail phenotype includes either a complete lack of vertebrae or a short tail with variable length. No dogs were found to have two copies of the mutation because it is thought that embryos with two copies of the mutation T/T are either die in the womb and reabsorbed by the bitch resulting in smaller litter size, or they die shortly after birth. Dogs with two copies of the normal gene will have normal tail. This conditioned is caused by the Brachyury mutation, the trait of inheritance is autosomal dominant which means that one copy of the mutation is enough to cause the natural short tail.
This test enables you to identify if a dog is docked or has a natural short tail.