A Skeletal Ossification Index for Neonatal Foals

Abstract

A skeletal ossification index (SOI) was devised to standardize the radiographic evaluation of the carpal and tarsal regions of newborn foals (less than two weeks of age). This index was based on two radiographic views of a carpus and a tarsus. Four grades of cuboidal bone ossification were discerned Grade 1 foals had some cuboidal bones with no ossification; Grade 2 was assigned when all cuboidal bones had radiographic evidence of some ossification; in Grade 3 the bones were small and round; in Grade 4 the cuboidal bones were shaped like the adult counterparts. Radiographs were taken of 24 neonatal foals of various gestational ages (range, 297-374 days). The relationships between the SO1 and two measures of newborn foal developmental maturity, gestational age and body weight, were assessed. There was no relationship between the sex of the foal and the SOI, but there was a relationship between the SO1 and the gestational age (one-tailed Spearman's rank correlation coefficient, r = 0.748) and between the SO1 and body weight (r = 0.77) for the 24 foals. For the ten foals with gestational ages less than 320 days, the relationship between body weight and the SO1 was significant (r = 0.953), but the relationship between gestational age and the SO1 was not significant (r = 0.605). The degree of ossification of the bones of neonatal foals that are born prematurely (< 320 days of gestation) or are "small-for-gestational age" at birth may be incomplete, and we suggest that radiographs of these regions should be made to assess ossification in foals in these two high risk groups. Veterinary Radiology, Vol29, No. 3, 1988; pp. 21 7-222.

Bullous emphysema with haemorrhage in a premature foal

“…Bilateral nystagmus, hyperextension of all 4 limbs and opisthotonus were present. Radiographic examination of the carpal and tarsal bones showed incomplete ossification – Adams Poulos Grade 2 (Adams and Poulos 1988), which was consistent with prematurity together with small body size, convex shape of the forehead and soft ears. The foal was haemoconcentrated (packed cell volume 48 l/l; reference range [rr] 31–42 l/l; total protein 55 g/l, rr 42–59 g/l).…”

Maternal dexamethasone treatment in late gestation induces precocious fetal maturation and delivery in healthy Thoroughbred mares

“…Physically, the foals from dexamethasone treated mares had similar bodyweights (P = 0.1) but significantly (P<0.05) lower CRL than the control foals. They did not show laxity of the fetlock joints and radiographs revealed normal ossification of the hocks and carpal bones ( grade 3 or 4 , Adams and Poulos 1988). Foal bodyweight gains were similar for both groups up to weaning at 6 months (controls: y = 8.13x + 59.6, r 2 = 0.995; treated: y = 7.75x + 51.6, r 2 = 0.996).…”

Description of a Well Preserved Fetus of the European Eocene Equoid Eurohippus messelensis

“…Its back is situated ventrally and the limbs point dorsally with respect to the vertebral column of the mare, whereas the head is close to the birth channel. By analogy with extant pregnant mares of Equus caballus [18], the stage of ossification of long bones and the development of the deciduous dentition (dP 4 already erupted) indicate that birth was imminent. The forelimbs of the fetus are not yet stretched towards the birth channel and the thorax is not yet turned into a dorsal position.…”