Ken R S Fisher

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Situs inversus is a rare congenital anomaly wherein the normal, left-right organ location is inverted. The anatomical inversion (heterotaxy) is usually detected in routine radiography or other medical interventions. A 5-month-old Holstein heifer calf was identified as a suspected situs inversus totalis during abdominal surgery. Following surgery the calf(More)
Gross anatomical analysis of a derodidymic monosomic stillborn male calf from an embryo transfer recipient was carried out. Two normal heads were present on two necks which were fused at the shoulders. Although the ribs were abnormal in shape and number, there was one trunk and four legs. The vertebrae were double and partially fused from the thoracic(More)
Preweaning mortality in piglets constitutes a major loss to the swine industry. Congenital defects account for a small but significant proportion of these losses. To implement appropriate strategies to reduce such losses, it is necessary to identify the specific causes and their relative importance. Consequently, a mail survey of swine production in Ontario(More)
BACKGROUND Conjoined twins with a doubling of all cranial structures, having two vertebral columns along their entire body length yet with a single pelvis, have not been described in the literature. The cause of conjoined twinning is incompletely understood; however, two main theories (fission and fusion) have been proposed and disputed. METHODS A(More)
This study provides an accurate, anatomical description of the rabbit's lumbosacral spinal cord. Following humane euthanasia, 64 rabbits were radiographed and dissected. The number of thoracic (T) and lumbar (L) vertebrae was 12T/7L in 43.8%, 13T/6L in 32.8%, and 13T/7L in 23.4% in the 64 rabbits studied. The 13th ribs were rudimentary, asymmetric, or both(More)
The clinical and anatomical features of a live-born diprosopic lamb are described. There are no complete anatomical analyses of two-faced lambs in the literature despite the frequency of conjoined twinning in sheep. The lamb had two heads fused in the occipital region. Each head had two eyes. The pinnae of the medial ears were fused. Caudal to the neck the(More)
A live-born, one-day-old diprosopic piglet was presented to the Ontario Veterinary College. The piglet had a normal body with two heads, joined in the occipital region. There were two complete snouts, four eyes and three ears. The lower jaws were immobile because of overlapping mandibular rami. Although there was only one vertebral column, the bodies of the(More)
Schistosomus reflexus (SR) is a rare and fatal congenital disorder. Primarily observed in ruminants, its defining features include spinal inversion, exposure of the abdominal viscera because of a fissure of the ventral abdominal wall, limb ankylosis, positioning of the limbs adjacent to the skull and, lung and diaphragm hypoplasia. Variable components of SR(More)
In a study of swine congenital anomalies, nine newborn piglets with varying degrees of optic hypotelorism including cyclopia were collected. Nasal and maxillary development were abnormal in all animals regardless of the degree of eye fusion. All animals except one had intact upper lips and hard palates that carried two or three small extopic teeth. The(More)