DYSTOKIA BY DISPLACEMENT. 281 



ever, pregnancy is advanced, the great size of the organ, together with its 

 weight, brings it in contact with the parietes of the peritoneal cavity, and 

 if there happens to be a weak part or a rupture, however slight, the heavy 

 uterus gradually forces itself through, and may in time escape altogether 

 from the abdomen, along with other viscera. 



It would appear that laceration of the abdominal walls may occur in 

 other ways than through external traumatic influences, or any appreciable 

 occasional cause ; and it would also appear that, in some animals, there 

 is a kind of predisposing relaxation or softening of the abdominal muscles, 

 which leads to their being unable to support the gradually increasing 

 strain thrown upon them by the heavy uterus, and its oftentimes very 

 lively and energetic inmate. The muscles are stretched and attenu- 

 ated, their fibres are separated and some of them may rupture, and in 

 this way is formed a rent, which gradually enlarges from the increasing 

 pressure. Then a tumor appears externally and towards the lower part 

 of the abdomen, though always a little to one side — usually the left in' 

 the Mare, the right in the Cow, and not unfrequently in front of the pubis 

 in the mammary region. This tumor, when first noticed, is about the 

 size of a child's head, and not clearly defined ; but it rapidly enlarges, 

 and in a few days may acquire prodigious dimensions : descending as low 

 as the hocks, or even nearly to the ground, pushing the mammae to one 

 side or carrying them with it, and extending almost as far forward as the 

 sternum, giving to the abdomen a singular appearance (Fig. 67). 



These extraordinary herniae are most frequently witnessed in Cows, 

 though several veterinarians — among others, Lecoq, Binz, Leconte, Serres, 

 Lafosse — have seen them in Mares. In very many instances they are due 

 to violent efforts, kicks, blows, and other external injuries. 



When the hernia is recent, and especially if it occurs in the mammary 

 region, it is generally surrounded by a considerable cedematous swelling. 

 This swelling disappears after parturition, though the hernial tumor 

 itself does not diminish in volume, the digestive organs having occupied 

 the space previously held by the foetus. Then the animal has a still more 

 singular appearance, perhaps ; for owing to this emptying of the abdom- 

 inal cavity, the belly is wonderfully retracted, and the flanks are so 

 drawn together that the fingers may be made to touch through them on 

 each side. 



Before parturition, palpation of the tumor enables the foetus to be 

 distinguished, the head, limbs, and body being felt, while its movements 

 are perceptible to the eye or hand. 



As a rule, and contrary to what might be surmised, this uterine hernia 

 does not appear to cause any loss of condition or inconvenience except in 

 progression, which it interferes with, and causes the animal to move with 

 its hind legs wide apart. Aptitude for labor is also somewhat impaired, 

 as may be imagined. 



Origin and Symptoms in Multiparous Animals. 



As has been mentioned, uterine hernia is observed in multiparous ani- 

 mals, but its manner of production, according to Saint-Cyr, would appear 

 to be different to what it is in uniparous creatures, this taking place in 

 the intervals between gestations. The length and mobility of the cornua 

 in such an animal as the Bitch, together with their close proximity to the 

 abdominal walls, sufficiently explain how they may pass into an opening in 



