Pulmonary pathology
			Mahaffey and Rossdale (1959) described the pulmonary pathology associated with convulsive foal syndrome along with the neonatal behavioral disturbance.  The condition was reported to follow an apparently easy delivery, but when attempting to get to his feet for the first time, the foal begins jerking his head up and down, becomes unsteady on its feet, and falls down.  The animal may emit a barking noise associated with rapid respirations and increased heart rate, then go into violent convulsions.  About half of the foals recover without any apparent residual effects, but may pass through a period of seeming blindness, wandering aimlessly about before learning to suck from their mother.
		In foals that died, aeration of the lungs was found to be incomplete.  Lung tissue was described as dark and dense, resembling fetal liver, as opposed to the pink feathery appearance throughout the lungs of foals that did not experience respiratory problems or convulsions in the newborn period.   Abnormalities of lung tissue was noted to be comparable to that described in human infants dying of pulmonary syndrome.  Mahaffey and Rossdale also noted that the ductus arteriosus was patent to a marked degree in the convulsive foals, an indication of incomplete transition to normal postnatal circulation.  They attributed these abnormalities to the conduct of human assisted parturition:
				"Variable degrees of traction are usually practised by attendants when the head and forelegs are emerging from the vulva.  The amnion is prematurely ruptured by hand, the legs are grasped and a pull is exerted upon them... the umbilical cord is ruptured with such haste that the newborn foal (weighing 100-120 lb.) is deprived of an average of 1020 ml. of blood and often 1500 ml. -- probably about 30% of its potential blood-volume.