Pathology in Practice

Abstract

The head and cranial portion of the neck of a 1-week-old sexually intact male polycerate (multihorned; 4-horned in this case) Jacob sheep (Ovis aries), the product of a 4-horned ram and a 4-horned ewe breeding, was presented for postmortem examination. The lamb had been born weak and unable to stand. Gradually, the animal lost its ability to eat and died shortly after. This lamb was 1 in a set of triplets. Within the triplet group, 1 lamb was born dead (horn number not specified) and 1 male 4-horned lamb was clinically normal. Breeding of this sire to 5 additional 4-horned ewes in the flock produced 8 lambs (4 clinically normal and 4 clinically affected). Of the 4 clinically affected lambs, 2 were unable to stand at birth. One of these initially recumbent lambs was hand reared, became ambulatory, and survived with persistent hind limb ataxia (Supplementary Video S1). Of the 2 clinically affected lambs able to stand at birth, 1 became recumbent by 1 week of age and was euthanized and the other survived with persistent slight hind limb ataxia, described by the owner as a wobble.