The appetite is diminished. The animal wastes; the secretion of milk diminishes, and signs of chronic gastro-enteritis may be noted. The perversion of appetite still continues; rags, decomposing or filthy materials, pieces of old shoes, etc., are eaten, and it is not surprising that such substances should have an unfavourable effect on the mucous membrane of the digestive tract.
The wasting process slowly leads to marked emaciation, and after an interval of from six months to a year, or even two years, the patients die in a state of complete exhaustion. The lesions found on post-mortem examination are those of various diseases capable of producing depraved appetite or simply lesions of chronic gastro-enteritis.
Diagnosis. The diagnosis presents no difficulty. The important point is to discover whether or not there exists some previously unrecognised primary disease.
Prognosis. The prognosis of this condition is grave, because depraved appetite is frequently only a symptom of some incurable disorder, or because the changes in the digestive mucous membrane are already too far advanced to permit of much improvement.
The lesions comprise: general emaciation, presence of a yellow serum in the fatty tissue, muscles pale and flabby, catarrh of the mucous membrane of the stomach and bowel. The blood seems less in quantity and coagulates feebly or not at all.
Treatment. The treatment should be directed against the primary cause, if such exists (osseous cachexia, pasteurellosis, gestation, etc.).
In other cases a change in management and in feeding, and the administration of food rich in mineral salts like chlorides, carbonates, and phosphates of lime, soda or potash, produces the best possible results. The leguminous foods, sainfoin, clover and lucern, are to be recommended. The animal, if formerly stabled, should be turned out and its living conditions entirely altered.
It is often useful to place a block of rock-salt in the manger; when hyperacidity of the stomach is suspected lime water, chalk, or magnesia should be given. Where digestion is weak or slow HCl, pepsin and vegetable bitters are indicated. Nevertheless, one sees cases which refuse to yield to any of the ordinary methods. In treating these, Lemke has recommended the subcutaneous injection of chloride of apomorphine, a drug which may be regarded as a true specific. The doses vary between 1½ and 3 grains, and an injection is given once a week for three weeks in succession. After this the tendency to pica is said to disappear and the general condition to improve. The treatment must be repeated every three months in countries where depraved appetite appears general and permanent.
It is difficult to understand by what mechanism this drug produces the effects attributed to it, but those who have employed it speak very highly of its action.
We may add that in addition to the different modes of treatment, it is not infrequently necessary to hastily perform gastrotomy in order to avoid fatal consequences, which would otherwise follow indulgence in this habit. When an animal has swallowed a considerable quantity of linen, for example (and Moussu has seen cases in which many pounds weight had been devoured), immediate intervention is required to avoid intestinal obstruction. Furthermore, when the history is quite clear gastrotomy allows the entire mass of foreign bodies, ingested at different times, to be removed.