DEPRAVED APPETITE IN THE OX.
Causation. In the bovine species depraved appetite occurs in adult, debilitated animals, which are often, though not always, suffering from some well-marked digestive disturbance.
The frequency of this symptom, and the peculiarities in its occurrence, have caused it to be referred to a large number of different causes, among which may be mentioned bad hygiene, chronic gastro-enteritis, tuberculosis, osseous cachexia, pasteurellosis, gestation, etc.
It is very certain that the peculiarity in the appetite is, above all, the result of incomplete and irrational alimentation. The animal has certain special requirements, to meet which the food must be of suitable composition. If these alimentary and digestive conditions are not fulfilled, depraved appetite may occur, even in animals which appear well nourished. Certain authors refer the appearance of this condition to want of certain soda salts in the daily ration, and, in support of this opinion, they point to the frequency of the disease in mountainous regions where the geological formation is chiefly granite, as in the Black Forest. Alluvial soils are supposed not to produce it. It certainly seems more common on soils lacking in certain constituents or exhausted by repeatedly growing certain crops. Nevertheless, in France it might be urged that pica occurs equally on all kinds of soil, and a German author, Lemke, ascribes this perversion of nutrition to the want of phosphorus. Haubner and Siedamgrotsky attribute it to a nervous disorder. All causes which exhaust the organism, especially all chronic diseases of digestive origin, may induce aberration of appetite.
Permanent stabling, confinement, absence of sunlight, want of exercise and pure air contribute to the general debility which predisposes to attack. Dry seasons, by reducing the supply of food, have a similar effect.
In tuberculosis and in pasteurellosis, it is the general organic decline which produces these puzzling changes in appetite. Similarly the influence of gestation depends on the superadded demands on the organism caused by the development of the fœtus.
Symptoms. The symptoms may be divided into two phases.
In the first phase, the animals still preserve their appetite, but whenever they have an opportunity they eat earth, sand, manure, litter saturated with urine, plaster, etc. They lick the walls, the boarding, the mangers and the trees, and they chew and swallow linen spread out to dry.
This phase may continue for a very long time, three to four months or more, provided no acute complication results from the eating of such foreign material. There is no fever, but the appetite, although well preserved, is often capricious, and the ordinary food is eaten slowly.
In the second phase, which frequently marks the development of complications produced by the passage, contact, or prolonged sojourn of various materials in the digestive tract, fever appears, little marked as a rule, but continuous in character.