Aswad, Aziz Salman Sadiq

2018-01-31T11:16:08Z

2018-01-31T11:16:08Z

1972

The anatomy, development and histopathology of the distal phalanx (PIII) and the cartilages of the equine hoof were studied by radiological and histological techniques. Chemical analyses of ash, calcium, magnesium and phosphorus were also included.

A well defined distal palmar process was present in a 5 month fetus. At this stage, the proximal articular surface of PIII was still cartilaginous; its development was completed 5 months postnatally. Side bone was detectable a month later. The notch of the palmar process may be converted into a foramen any time after 2 years of age. Throughout development, the cartilages of the hoof were fibro- elastic and although directly continuous with the proximal palmar process of PIII, they were attached to the distal palmar process by a short ligament.

The side bone developed consistently in all cartilages and was invariably present from 6 months onwards. A means of classification as short, medium, long and marked has been suggested. The short type was the most frequent whereas the others were seldom seen in animals under 3 years of age. The longer types were more commonly observed in the fore than in the hind feet and some bilateral symmetry was present. Although the presence of this bone has been claimed to be a factor in causing lameness, this was not verified.

Bony islands were seen at different sites in the cartilaginous plate and in the short ligament which attached the distal palmar process to the solar border of the cartilage of the hoof; those of the cartilaginous plate originated near to cartilage canals. A radiological dense area was sometimes seen in the region of the palmar process in animals older than 2 years. This was due to the presence of the bony bridge which converted the palmar notch into a foramen.

Side bone was formed by ossification and not calcification. Bone growth from the proximal palmar process of PIII is one of the factors involved. Its osteogenesis was a normal process of ossification extending from the proximal palmar process of PIII. Bony islands also occurred in the cartilage and at the level of the distal palmar process. There was no evidence of inflammatory reaction but necrosis and "non- provisional" calcification of the cartilage plate occurred and became more marked with age.

There was a significant difference between the mineral composition of the side bone and that of the adjacent part of PIII. This was related to differences in the stages of developments of the two regions.

http://hdl.handle.net/1842/26158

The University of Edinburgh

Annexe Thesis Digitisation Project 2017 Block 15

Ossification of the cartilages of the horse's hoof (side bone)

Thesis or Dissertation

Doctoral

PhD Doctor of Philosophy