ASPHYXIA NEONATORUM 369 



^tiolog]j. — 1. Viohnt uterine contractions during the pre- 

 liminary and expulsive stage. As a consequence of an early- 

 rupture of tlie foetal membranes, the uterus contracts, the 

 placental circulation is disturbed, so that death of the calf 

 may follow insufficient blood supply. 



2. Retarded expulsion. When head and fore legs are in the 

 pelvis, the allantoic fluid is mostly discharged and the uterus 

 contracted to a certain extent. Should disturbances be present 

 in the parent or young, interfering with birth at this moment, 

 the blood supply from the placental vessels is no longer suffi- 

 cient, and dyspnoea results. 



When one-half of the calf is born — that is, when the 

 anterior half of the body is born — and the trochanteric diameter 

 lies in front of the pelvic inlet, or when in the croup presenta- 

 tion the hind legs lie in the parturient passage, the navel 

 string usually tears quickly and the placental blood supply 

 ceases, dyspnoea being the result of a retarded birth. 



3. Inspiration of amniotic fluid. Compression or rupture 

 of the navel string causes inspiratory movements. In conse- 

 quence of it amniotic fluid, especially in the croiip presenta- 

 tion, may enter the air passages, thus interfering with the 

 entrance of air. 



Symptoms.— When the calf is born, the owner is soon 

 inclined to look upon it as dead ia case no inspiratory move- 

 ments are noticeable. Nevertheless it is possible that the 

 young animal can be saved by proper treatment. In most 

 cases of asphyxia respiration immediately after birth is deep 

 and slow, with long intervals. The heart's action often is very 

 weak. Movements of the voluntary muscles are frequently 

 wanting. This state may persist for ten to fifteen minutes; 

 when respiration becomes less deep and slow, the heart's action 

 becomes stronger and some inspiratory movements with a 

 rattling noise manifest themselves. During the asphyxic state 

 death may occur at any moment. 



Therapeutics.— First the amniotic fluid must be removed 

 from the mouth. This is best done with the fingers. Often 

 the tenacious slime can be removed in the shape of a long 



