TDK conference 2017

A dog with six limbs, having survived almost a week, was macroscopically examined. We documented the anatomical changes: abdominal organs, skeletal and muscular structures of the hind quarter were described.

Reasons for congenital malformations are frequently different teratogen issues, like genetic factors, abnormalities of chromosomes, environmental influences and mutant genes – or the combination of the above mentioned ones.

Birth defects might be less severe and not even interfere with regular functions, or might be lethal. Dysmelia (malformations of extremities) give a few percentage of congenital malformations, might however still be important. Dipygus (a duplicated hind quarter), polypodia (doubled extremities) or reduced development of the extremitie(s) are severe alterations. Additional of fused digits or splitted distal limbs are frequently not preventing regular functions, thus are considered as minor defects. Pathological changes are, however, not necessarily restricted to the extremities: it is not unusual to have alterations in abdominal organs as well. This was also the case in the puppy described in current paper.

She was the only puppy in the crossbreed litter having shown malformations. The supernumerary, additional hind limbs showed bony and muscular features similar to that of a normal limb. Beside bony structures as the pelvis and some vertebrae also the distal section of the colon and parts of the urogenital tract were duplicated.

The literature describes just a few cases of congenital duplications of the caudal region in the dog, thus our paper indicates one of the rare findings.