Short tail

The presence of short tail variant of the T-box gene is related to a reduced tail size.

Definition

The short tail trait results in a phenotype with a small or practically non-existent tail size. The variant responsible for the trait is found in the T-box gene, a gene essential in the proper development of various tissues and organs of the dog, such as the limbs.

Genetic basis

The variant responsible for the short tail phenotype has a dominant inheritance, therefore, a single copy of the c.189C>G variant is sufficient to express this phenotype. In this case, there is a 50% probability that the mutation can be inherited by the offspring of the carrier dog. However, the presence of two copies of the c.189C>G variant is not compatible with life because this situation causes fetal death of the puppy. For this reason, mating two dogs carrying the c.189C>G variant is not recommended because of the possible reduction in litter size. It is possible that there are other as yet unknown genetic factors involved in the development of the trait.

Other relevant information

Despite being a mutation, the short tail trait can have health benefits for the dog. Dogs with short tails reduce the risk of injury during physical activities such as jumping, climbing or running. In addition, it is easier to maintain proper hygiene of a short tail than a long one, thus avoiding possible skin infections. The trait is also called "bobtail" and is commonly found in the Pembroke Welsh Corgi, Miniature American Shepherd, Old English Sheepdog, Australian Cattle Dog and Boston Terrier breeds.

Bibliography

Haworth K, Putt W, Cattanach B,et al. Canine homolog of the T-box transcription factor T; failure of the protein to bind to its DNA target leads to a short-tail phenotype. Mamm Genome. 2001 Mar;12(3):212-8.

Hytönen MK, Grall A, Hédan B,et al. Ancestral T-box mutation is present in many, but not all, short-tailed dog breeds. J Hered. 2009 Mar-Apr;100(2):236-40.