Peritonitis is inflammation of the serous membrane which lines the cavity of the abdomen and covers the contained organs. The inflammation may begin at a certain spot, and rapidly spread throughout the whole extent of the membrane, being confined exclusively to the peritoneum from first to last. Those portions of the peritoneum which cover the liver, the stomach, the intestines, etc., are more liable to take on inflammatory action than that portion of it which lines the walls of the abdomen. The peritonitis is then partial, and is limited to the particular organ which the serous membrane invests; and it is the secondary result of inflammation beginning in the proper tissue of that particular organ.

* See "Glyatering," in Appendix.

Peritonitis, when caused by mechanical violence, such as the kick of a horse or any other animal, or by a penetrating wound, is called traumatic. Penetrating wounds do not always set up inflammation of the peritoneum. Thus, Dr. Richardson, in his most interesting experiments, injected a strong solution of lactic acid into the peritoneal cavities of two dogs. On examination after death, the peritoneum was found uninjured.

Amongst the causes of peritonitis may be enumerated, exposure to cold and damp, parturition, errors of diet, strangulation, and obstruction of the bowel, etc. As a secondary disease, peritonitis may be excited by such local inflammation as hepatitis, gastritis, enteritis, etc.

There are two forms of peritonitis, the acute and the chronic, and both forms may be either general or partial.

The acute form is sometimes, but not always, ushered in by shivering and feverishness. The pulse soon becomes hard, frequent, and small, and either strong or feeble; the breathing is catching and panting; the nose and mouth are dry; there is no appetite, but great thirst. The dog frequently cries out or otherwise shows that he is suffering great pain; he is either restless, and constantly walks from one place to another, or lies on his side stretched out at full length. The abdomen is extremely tender to the touch, and tense and tympanitic at first; later it becomes gradually enlarged from effusion of serum. The enlargement due to tympanitic distention gives a clear sound when the part is percussed; that due to serous effusion a dull sound. The bowels are generally confined and the urine scanty. Death is preceded by cessation of pain, increase of enlargement, increased frequency and feebleness of pulse, clammy sweats, and exhaustion.

The disease may terminate in return to health, or in dropsy of the belly, or in the chronic form.

The chronic form may succeed the acute. In dogs, chronic peritonitis is a rather frequent and a primary disease.

The symptoms of this form are, loss of appetite and spirits; variable appetite, sometimes good, sometimes bad; progressive emaciation; tucked up belly, which on examination is found hard and contracted, and marked by two tense longitudinal ridges; occasional whining and disposition to escape from notice; gradual exhaustion and death in some cases; or recovery in a fair proportion. Towards the last ascites comes on.

Treatment

Aconitum * is particularly indicated at the beginning of the disease, and especially when the abdomen is tender to the touch, and the animal is evidently suffering much pain. In many-cases this medicine is alone sufficient to check the disease.

* For the dose, consult the "Introductory Remarks".

Belladonna is useful when the abdomen is tender, tense, and distended. These two medicines maybe given alternately.

Arsenicum is indicated when sudden cessation of pain is followed by quick, feeble pulse, cold legs, and collapse. These are highly unfavourable symptoms.

The treatment of the effusion that sometimes follows peritonitis is given under "Ascites."

Food, Etc

After recovery it is indispensable not to give indigestible or seasoned foods, and even plain food must be allowed only in small quantities. When symptoms of exhaustion come on, give beef-tea, brandy, etc.