In speaking of umbilical hernia we pointed out that the escape of the abdominal contents took place through a natural opening (navel or umbilical opening). In ventral hernia it is otherwise. Here the muscular and fibrous structures of the belly are ruptured by some form of violence.
Fig. 119. - Ventral Hernia.
The more common causes of this accident are kicks, horning by cattle, falling on to blunt stakes or posts while jumping, sudden and forcible compression in passing through narrow gates, straining in the act of parturition, or when cast in a drain.
Ventral hernia may occur in any part of the abdomen, and will vary in size in accordance with the extent of the rupture. It may be no larger than a cricket-ball, or it may extend from the groin towards the girth for a considerable distance. The contents of the sac usually consist of intestine or omentum, or both may be present at the same time.
When of recent occurrence the enlargement may be much in excess of the actual size of the hernia, owing to the inflammatory swelling excited in the injured tissues at the time of the accident. The contused part is hot and painful to pressure, and if the structures have been seriously damaged further enlargement may take place in the course of the formation of an abscess. The writer has known several quarts of matter to form around the hernial sac in the region of the Hank. It is not until this extraneous swelling has been removed that the precise extent of the rupture may be determined. In an old hernia, when the inflammatory tumefaction has passed away, the hole in the belly may generally be felt by deep pressure along its circumference. When composed of intestine it will be found to fluctuate to pressure, and to vary in size from time to time according as the escaped bowel may contain much or little food.
Small ventral hernia, like umbilical hernia, may disappear spontaneously, or undergo more or less reduction in size.
When dealt with at the time of its occurrence, the first indication of treatment is to reduce the inflammatory action and swelling by hot fomentations and physic, and prevent further escape of abdominal contents by the application of a compress, which may be extemporized out of a thick pledget of tow, and a long broad bandage made out of an old rug. As the inflammatory swelling subsides, the compress should be drawn tighter round the body. At this time, and throughout the treatment, the patient should be kept on half-rations, which should consist of sloppy bran. Large quantities of bulky food will tend to force the bowels through the opening and prevent its closure. If the rupture is situated backward, the hindquarters of the animal must be raised by underpacking with litter to displace the weight of the abdominal contents forward. So soon as the inflammation has dispersed, a blister should be applied over and round the enlargement, and repeated again and again. The compress must be allowed to remain on while the blister is acting, and until it is repeated.
Old hernia must be reduced by either clams or ligature, as in the case of umbilical hernia, and under the same precautionary measures. Where they do not interfere with the animal's services they should not be interfered with.