io68 Veterinary Obstetrics 



sure of the palate, in a colt which lived to about one year old, 

 when it was destroyed as incurable. 



The defect consists of an arrest in the development of the 

 palatine laminae or arches, which fail to come in contact and fuse 

 upon the median line, thus forming a direct opening from the 

 mouth into the nostrils, as indicated in Fig. 35 on page 298. The 

 fissure permits the passage of food from the mouth into the nasal 

 chambers, from whence it drops out through the nostrils. In 

 this way the young animal is placed at a serious di.sadvantage 

 by losing a large part of its food through the nostrils, and thus 

 undergoes partial starvation. At the same time, the lodgement 

 of food in the nostrils irritates the parts, and its discharge there- 

 from presents so repulsive an appearance that the animal is ren- 

 dered valueless. 



The handling of fissure of the palate, in domestic animals, is 

 virtually barred by the great depth of the oral cavity, which 

 prevents the surgeon from attempting to bring about an adhesion 

 of the two sides by means of an operation, though in some cases 

 it might be theoretically possible. 



8. Persistent Foramen Ovale. Cyanosis. 



In describing the fetal circulation on page 328, it was mentioned 

 that, since the lungs are inactive up to the time of birth, their office 

 must be performed by the placenta. In order that the blood 

 leaving the right ventricle may readily pass to the placenta of 

 the mother, there exists in the fetal heart a communication, 

 the foramen ovale, between the two auricles. This should 

 normally close at about the period of birth, but sometimes does 

 not, and as a result the new-born animal suffers from cyanosis 

 or a mixed circulation, in which the arterial blood assumes a 

 venous character and gives to the visible parts a blue color. This 

 defect is very rare in animals When present it is usually accom- 

 panied at the time of birth by extreme weakness, with rapid 

 respiration and a deep blue color of the visible mucous mem- 

 branes, the consequence of the partial asphyxia from which the 

 animal is suffering. 



The condition is beyond remedy. Spontaneous recovery may 

 occur. If the defect persists the animal may survive for some 

 time. Zundel records a case in a horse which reached the age 



