Natural bob tail

From Dog

Natural bob tail is an autosomal-dominant genetic disease of dogs characterized by a shortened tail.

This disease has been reported in the Australian Shepherd, Rottweiler, Boxer and Pembroke Welsh Corgi and is caused by a mutation located in the T-box transcription factor T gene (C189G)[2]. Most dogs born are heterozygously affected and analysis of offspring from several independent bobtail x bobtail crosses indicates that the homozygous phenotype is embryonic lethal.

There are various levels of severity that occur, from almost no tail to a shortened tail.

Although this condition poses no health concerns, in the case of a homozygous dominant dog, the allele becomes lethal in the embryonic stage and the affected dog does not survive[3].

Gene testing of at-risk dogs can be done by buccal swabs using PCR assays.


  1. ASAP Labs
  2. Hytönen MK et al (2009) Ancestral T-box mutation is present in many, but not all, short-tailed dog breeds. J Hered 100(2):236-240
  3. Haworth K et al (2001) 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. Mammalian Genome 12(3):212-218