ABOMASAL INDIGESTION.
Primary indigestion in the abomasum appears to be rare in adults, for until the present time no one has given a sufficiently characteristic description of this disease to enable it readily to be recognised. On the other hand, it is to be presumed, although final proof has certainly not been furnished, that in cases of gaseous indigestion, or of impaction of the rumen, the abomasum, whose physiological action is predominant, must simultaneously suffer.
Primary abomasal indigestion, on the contrary, is common in young animals before weaning, so that the condition has been given the name of “milk indigestion.” It could not very well be otherwise, for the abomasum is the only one of the gastric divisions which in ruminants is active during the first few weeks of life. At this period it is larger than the other gastric reservoirs; and the rumen, the reticulum, and the omasum do not undergo great development till weaning begins.
Causation. Milk indigestion attacks young animals, under varying conditions.
In animals suckled by the mother the disease rarely occurs, but yet when the mothers are good milkers, like the Flemish, Norman, Jersey, and Holland breeds, and when there is too long an interval between the feeds, calves, which are naturally greedy, and in addition are hungry, are apt to take too large a quantity of milk—in fact, they often gorge to the fullest possible extent. Owing to its over-distended state the abomasum either fails to secrete sufficient of the rennet ferment necessary for coagulating the milk or secretes an insufficiently active ferment. The first stage of digestion remains incomplete, giving rise to so-called “milk indigestion.”
When the cows are employed in ploughing, etc., or in drawing carts, not only are the calves fed at long intervals, but the milk is not always of proper chemical composition even in the udder. As a result of work, fatigue, over-exertion and irregular feeding, the cow’s yield of milk for the time is less digestible than the normal supply, or may even prove irritant to the calf’s stomach. Milk indigestion is thus set up.
When the cows are fed on factory waste, like beetroot-pulp or brewers’ grains, toxic or irritant products may even find their way into the milk, which then irritates the little creature’s abomasum and produces gastric indigestion. Just as in the production of congenital alcoholism in man, the young animal is then ingesting, unknown to those responsible for its well-being, chemical substances which produce various pathological changes.
But milk indigestion is commonest of all in calves fed by hand. The food usually given is a mixture of milk from the previous night, and skim milk or even butter milk. It contains lactic ferments and various microbes, some capable of producing toxic principles.
When swallowed and brought directly in contact with the mucous membrane these cause abomasal indigestion.
Symptoms. Soon after feeding, the little animal appears dull and somnolent, and shows moderate abdominal pain, suggesting trifling colic.