SYMPTOMS 201 



Calving is the chief predisposing factor. The manner in 

 which it acts as an accessory has not been definitely determined, 

 but is thought to be due to alteration in blood supply. It is 

 after easy calving when there has been little expenditure of 

 muscular or nervous energy that milk fever appears. Difficult 

 parturitions which, as a rule, occur at the time of the first or 

 second birth are rarely connected with parturient paralysis. 



Symptoms. — Milk fever usually begins with signs of rest- 

 lessness and occasionally signs of brain irritation may be 

 observed in the beginning. After these initial stages, the char- 

 acteristic signs of depression and paralysis appear (Figs. 69 and 

 70). First, the cow shows a. weakness in the use of her hind 

 parts; and steps unsteadily or staggers when attempting to 

 move or walk, may fall and struggle to rise again. The cow no 

 longer notices her calf or her feed. The weakness increases 

 and the cow lies down or falls and is unable to regain her feet. 

 The animal's temperature, which becomes sub-normal, may be 

 slightly raised at this period. The cow may lie on her breast- 

 bone with her feet beneath the body, and her head turned 

 round with the nose resting on the right or left, usually the 

 left flank. In this position the cow appears to be asleep. In 

 cases of extreme feebleness, the cow may lie on her side with all 

 four legs stretched out. If an attempt is made to lift the head, 

 it falls back powerless into its old position. The eyes appear 

 glazed, and the pupils are widely dilated. The upper eyelid 

 droops over the eyeball and is not moved when the eyeball is 

 touched with the finger. At this time unconsciousness is usually 

 complete. The tongue hangs loosely from the mouth, and breath- 

 ing is performed with snoring, groaning, and rattling noises 

 accompanied with great distention of the nostrils. The muscles 

 of the bowels become paralyzed, causing obstinate constipation 

 and at times bloating. This is usually accompanied by paralysis 

 of the bladder muscles causing cessation of urination. If either 

 or both of these organs continue to function, a favorable prog- 

 nosis can usually be given. The temperature which may be 

 raised at first becomes sub-normal. The pulse and heart-beats are 

 quickened. The body temperature is unevenly distributed, the 

 feet, ears, and horns being exceptionally cold to the touch. 



