Intracranial haemorrhage in pre‐viable, premature and full term foals

Abstract

Summary A neuropathological examination was carried out on the brains of 58 foals. Forty‐two were pony foals induced at various periods of gestation from 200 days onwards. Two were pre‐viable pony foals delivered by caesarean section and 14 were Thoroughbred foals (one set of twins, two stillborn, five premature, two dysmature, two convulsive and one induced). The only significant pathological change involved intracranial haemorrhage. Subarachnoid haemorrhage occurred in all of 10 pony foals induced before 301 days of gestation and in two pony foals born by caesarean section at 270 and 280 days gestation. Subarachnoid haemorrhage was also present in some pony and Thoroughbred foals born after 301 days gestation; the incidence usually appeared greater in those pony foals which survived for the shortest periods. Haemorrhage also occurred elsewhere in the brains, including the cerebral white matter, the molecular layer of the cerebellum and the medulla, but the intensity could not be related to either length of gestation or duration of survival. No other neuropathological changes were found that could account for the functional state of the animals, whether they were pre‐viable, premature, dysmature or convulsive.

Study of arterial blood pressure in newborn foals using an electronic sphygmomanometer

“…It is of interest that cerebral haemorrhages are found commonly in Thoroughbred foals and it has been postulated that these may be related to changes in vascular pressure during and after delivery. Similar lesions have not been reported in ponies, although subarachnoid haemorrhages are common, especially in premature pony and Thoroughbred foals (Adams and Mayhew 1984;Palmer, Leadon, Rossdale and Jeffcott 1984).…”

Fifty years of the British Equine Veterinary Association as a facilitator of progress in equine clinical science

“…1984; Webb et al . 1984) with the pharmacology of the newborn described in terms of drug disposition (Baggot and Short 1984), while pathology included a description of intracranial haemorrhage in previable premature and full‐term foals (Palmer et al . 1984).…”

“…This addressed the fetal/ maternal relationship in reviews of equine placental exchange and fetal physiology (Silver 1984), maternal and fetal endocrinology during late pregnancy and foaling, carbohydrate metabolism during pregnancy ) and the renin-angiotensin system (Broughton Pipkin 1984). In addition, new data were presented on the relationship between mammary development and secretions in normal spontaneous and induced premature parturition in the mare (Leadon et al 1984;Ousey et al 1984a) and other aspects of parturition were discussed (Stewart et al 1984;Ousey et al 1984b). Physiological and clinical studies on the foal were presented in relation to maturity Silver et al 1984;Rossdale et al 1984a;Fowden et al 1984b).…”

Hypoxic/Ischemic Encephalopathy in the Foal

“…Further, the observation of intracranial hemorrhage in foals delivered by caesarian section would appear to invalidate this concept. 8 Some authors have stated that HIE is most often associated with rapid, uncomplicated delivery 9 , yet HIE is also clearly seen in many clinical settings which can result in hypoxia of the fetus, such as dystocia, intrauterine umbilical cord compression, decreased placental blood flow, and premature placental separation. These observations, as well as extrapolation from human medicine, provide strong evidence that the pathophysiology must involve hypoxia and ischemia although not excluding the possibility that other factors also contribute.…”

“…Examination of the CNS will often find signs of cerebral edema, hemorrhage, or cerebral necrosis. 8,19 TREATMENT AND PROGNOSIS Treatment of foals with HIE must address the multisystemic nature of this disease. High quality nursing care is imperative and must include monitoring of blood gases, cardiac function, renal function, and nutritional status.…”