542 DIAGNOSIS OF INGUINAL HERNIA. 



(1) So-called interstitial inguinal hernia. This condition will 

 later be referred to. 



(2) Scirrhous cord, though the greater hardness of the entire 

 swelling scarcely allows of mistake. 



(3) Hydrocele. Collection of fluid in the vaginal sac may be 

 recognised by the swelling being easily displaced and occupying 

 the lower portions of the scrotum. Hydrops of the spermatic cord 

 may be at once recognised by its greater firmness and immobility, 

 and can only be mistaken for incarcerated hernia. 



(4) Hematocele, that is, distension of the scrotum, or of the 

 tunica vaginalis, with blood, presents the same appearances as hydrops, 

 but is often associated with oedema of the scrotal skin. 



(5) Inflammation of the skin covering the scrotum may, under 

 certain circumstances, give rise to suspicion of inguinal hernia, and 

 in all such doubtful cases examination per rectum must be resorted 

 to, when it is easy to determine whether or not bowel has entered 

 the inguinal canal. 



(6) Tumours of the spermatic cord and testicle develop slowly, 

 and are not dissipated by pressure. 



Course. In foals, spontaneous recovery often occurs, though 

 seldom later than the second year of life. Gross believes that good 

 feeding favours recovery, by producing a better muscular tone; 

 and distension of the intestine with firm contents, consequent on 

 hard diet, certainly assists reduction. On the other hand, the rupture 

 may gradually increase, particularly if work is heavy and the food 

 bulky, and in such cases incarceration often occurs. Cases like 

 Brinhall's in a three-year-old stallion are, however, very rare. He 

 saw a scrotal hernia suddenly develop, and two weeks later break, 

 in consequence of necrosis of the sac. An intestinal fistula was thus 

 produced, but closed again in a month without any assistance. 

 Perhaps this was a case of strangulation, but the result was certainly 

 very extraordinary. In exceptional cases inguinal hernia appears 

 in old animals and generally soon becomes strangulated. Such 

 cases are probably often due to a simple inguinal hernia developing 

 into the scrotal form, the former having been overlooked. In stallions 

 scrotal hernia may become so large as even to interfere with movement 

 of the hind-limb, or be injured by it. 



Prognosis. Inguinal hernia is always dangerous, because treat- 

 ment is difficult, and death often follows strangulation. The most 

 important elements in forming a prognosis are the age of the animal, 

 and the size and character of the hernia. 



Spontaneous recovery is rare in adults though common in young 



