522 SPORADIC DISEASES. 



of the system in this affection, not only prior to the occurrence of 

 the local cerebral congestion, but throughout its course, and 

 after the animal's death, when the vessels are found engorged 

 and the tissues loaded with effusion. 



I think that the particular congestion of the brain and its 

 meninges is determined by the state of mental excitement 

 which is always present at this period, and this argument is 

 borne out by the fact that the removal of the offspring from its 

 mother is a fruitful exciting cause of the so-called milk fever. 

 That the lower animals are capable of expressing strong maternal 

 affection is patent to all observers. Who has failed to witness the 

 restlessness, loss of appetite, and unhappiness of many a cow de- 

 prived of its calf ? and this is a fruitful source of derangement 

 of health. 



To exemplify this, a case of general paralysis in a she-goat came 

 under my notice some years ago, which I will here relate. 

 The goat's kids, four weeks old, were taken away from it by 

 the owner, who, on returning in about an hour's time, found the 

 poor animal completely paralyzed, moaning piteously, and evi- 

 dently in a state of great distress. It remained in this con- 

 dition for several days, when the owner brought it to the New 

 Veterinary College for my opinion. Wlien I saw it, it was 

 quite conscious, but powerless, lying at full length upon its side. 

 I kept it for several days, but it gradually sank and died. 

 Now in this case there was no cause of disease but mental dis- 

 tress, and if this be the case with the goat, most assuredly mental 

 distress may be a cause of derangement in the cow. In addition 

 to the removal of the calf from the mother, it is a common 

 practice to make sudden and violent changes in the animal's 

 diet. For the food to which it has been used, thin bran slops, 

 gruel, &c. are substituted : this of itself would be sufficient to 

 induce indigestion and serious constitutional disturbance. 



That middle-aged animals are more prone to the malady is 

 explained by the facts that the lactiferous powers are greater in 

 them than in the young, and that the functions of the ganglionic 

 nerves are more active, and consequently are sooner deranged. 



Atmospheric conditions have also to some extent an influence 

 in predisposing to the malady. During warm spring weather it 

 is much more prevalent than in cold seasons : from this cause 

 many newly calved cows are simultaneously attacked, leading 

 some to suppose the disease to be enzootic. 



