The T Locus mutation affects a gene involved in natural tail length development. If present, the mutation can disrupt the development of the dog’s tail which can result in a naturally short tail also known as a “bobtail”. This mutation is inherited in a dominant fashion which means only one copy of the mutation is required to produce a natural bobtail. It is important to note that a dog that inherits two copies of the T Locus mutation will likely not survive the development process which can result in reduced litter sizes.

All Breeds

A (CLEAR/NORMAL): These dogs have two copies of the normal gene and will neither develop a naturally short tail due to the T Locus mutation nor pass this mutation to their offspring.

B (CARRIER/AFFECTED): These dogs have one copy of the normal gene and one copy of the mutation associated with a naturally short tail. They will develop a naturally short tail and will, if bred, pass the mutation to 50% of its offspring, on average.

C (AT RISK/AFFECTED): These dogs have two copies of the mutation associated with a naturally short tail which can unfortunately lead to reduced survival rates in utero. These dogs will typically not survive the development process.