558 PERINEAL HERNIA. 



IX.— PERINEAL HERNIA. 



The posterior wall of the pelvis possesses in male animals only 

 one dilatation — the recto-vesical ; but in female animals there are 

 two — the upper the recto-vaginal, the under vesico- vaginal. Ex- 

 tension of one or other of these boundaries of the pelvis with entrance 

 of abdominal viscera into the space so caused is termed perineal hernia. 



This condition is most frequently seen in dogs, occasionally in 

 the cow, ewe, and rarely in the bitch, in which animal it usually 

 consists of a dilatation of the excavatio vesico uterina, which is 

 more exposed to strain on account of its lower position. In male 

 animals either the intestine or urinary bladder is found in the excavatio 

 recto-vesicalis, in females the hernia consists of the uterus, omentum, 

 bladder or small intestine. Frick, in the case of a pregnant cow, 

 saw a portion of the gravid uterus in the sac. 



Symptoms. In dogs a swelling, varying from the size of a man's 

 fist to that of a child's head, and possessing the known characteristic s 

 of a hernia, occurs close to the root of the tail and just over the ischial 

 tuberosity. In ewes it may be as large as a goose's egg, and appears 

 alongside the vulva. In the cow a round swelling, sometimes as 

 large as a man's head, arises close under the vagina, and presses 

 forward the labise. The hernia can be reduced and the swelling 

 dispersed by pressure, by raising the hind-legs, or by walking the 

 animal down-hill ; whilst it is increased by raising the fore-legs, or by 

 any cause which increases intra-abdominal pressure. Incarceration 

 very seldom occurs, though Siedamgrotzky noticed strangulation 

 of the urinary bladder in a dog. 



Causes and progress. Continuous contraction of the abdominal 

 muscles, difficult parturition, heavy draught, walking on the hind- 

 legs (dog), standing with the hind-quarters low (cows) and obstinate 

 constipation are known to favour production of perineal hernia, 

 but its immediate cause is a mystery. It may exist for long periods 

 without causing trouble, for, on account of the great width of the 

 hernial opening, incarceration is exceedingly rare, though, according 

 to Stockfleth, it sometimes impedes delivery in ewes, because the 

 vagina is pressed into the hernial sac during labour, and becomes 

 more or less folded. Cows with this defect should not be used for 

 breeding. In Frick's case assistance was required to deliver the calf 

 as the fore-legs became fixed in the hernial sac. Dogs may have 

 difficulty in urinating and the cause may be referred to the prostate. 

 Doubt as to the nature of the swelling can be removed by exploratory 

 puncture, employing a clean grooved needle or fine trocar. 



