HERNIA AT THE NAVEL. 293 



from operating if the tumour be harmless in its effects. If, how- 

 ever, it becomes so large as to seriously impair the usefulness of 

 the animal, or if painful symptoms set in, we should, after having 

 placed the patient on his back, try to return the tumour in the 

 manner described for the treatment of acute inguinal hernia, 

 after having removed the testicle (supposing the animal to have 

 been an entire), and put on a clam close below the inguinal ring. 



Hernia at the Navel {Ufnbilkal Hernia). 



This form of hernia is the protrusion through the navel, of 

 bowel or of its connecting membrane. It is consequently situated 

 in the middle line of the abdomen and can scarcely escape the 

 observation of the most inexperienced person. 



CAUSES. — Hereditary predisposition is well marked in this com- 

 plaint. " It may exist at birth, but, as H. Bouley wisely remarks, 

 this so-called congenital hernia may very probably be the result 

 cf the pulling which the navel-string underwent at the time of 

 foaling. However it may be, umbilical hernise usually occur during 

 the first two or three months after birth ; that is to say, while the 

 opening at the navel is becoming obliterated, and the tissue at 

 that place is becoming consolidated. They can, however, appear 

 later, and may result from more or less violent strains done when 

 the foals are jumping and playing. At other times, these strains 

 are induced by intestinal irritation, accompanied by diarrhoea, or 

 constipation with straining. But, however the strain may take 

 place, the abdominal muscles contract and push the intestines 

 towards the wall of the belly. Then, if they find an opening, or 

 even a weak spot, like the ring of the navel while it is undergoing 

 the process of becoming blocked up, they select it, and a hernia is 

 produced " (Peuch and Toussaint). 



SYMPTOMS. — This hernia, the situation of which clearly shows 

 its character, may vary in size from that of a hen's egg to that 

 of an ostrich's egg, or even bigger, and may be hemispherical or 

 pear-shaped. The tumour, if pressed upon with the hand, espe- 

 cially if the animal is placed on his back, will disappear, to return, 

 however, when the pressure is removed. If it be composed of in- 

 testine, it will be soft and elastic when the bowels are empty, and 

 doughy when they are full of semi-solid matter. In any case, the 

 tumour will feel more elastic when composed of intestine, than 

 when formed of its connecting membrane, which, naturally, will 

 not vary in consistence. If intestine be present, movements and 

 abdominal rumblings may be detected in it. This hernia rarely 

 gives rise to serious consequences; because its contents are com- 



