DEPRAVED APPETITE IN CALVES AND LAMBS.
Causation. Depraved appetite is commonest in calves and lambs when the animals are insufficiently nourished, or when the mothers are suffering from chronic debilitating diseases and are therefore yielding milk poor in fat and in mineral constituents. In a few rare cases it is impossible to discover what causes the young animals to devour these foreign materials. Even fully-grown sheep, when shut up together in winter, acquire the habit of chewing each other’s wool, sometimes to the extent of virtually depilating their fellows and accumulating wool balls in their stomachs.
Symptoms. Calves have a tendency to lick themselves or their neighbours, and thus little by little collect a varying quantity of hair which they swallow. When this habit of licking is little marked the quantity of hair ingested may not be dangerous; but in the contrary case the hair (which cannot be digested) accumulates and is permanently retained in the abomasum. It soon becomes converted into masses, cemented together with mucus, and forms round balls, to which the name of œgagrophiles has been given. If these œgagrophiles, or hair balls, are of small size, they prove of trifling importance; but too frequently they attain considerable dimensions and obstruct the pylorus or the intestine. The young calves then refuse all nourishment, and die in twenty-four to forty-eight hours in a state of complete exhaustion or after a series of epileptiform attacks.
In lambs the complications due to depraved appetite develop in a similar way, but the wool swallowed is obtained from the mothers. The lambs first suck the locks of wool, then tear them off and swallow them. So long as these peculiarities of appetite are little marked no bad results follow; but if the shepherd is careless, and fails to note the condition of his young flock sufficiently early, accidents occur.
The wool is not so easily converted into balls as is hair, but it soon accumulates in the pyloric region or in the intestine, and forms obstructing masses. The little patients lose appetite and lie down in corners, where they are found dead after twenty-four to forty-eight hours. The masses of wool or of hair are rarely passed with the excrement; more frequently they are vomited, but this again is exceptional; usually they become arrested at the entrance to the pylorus. The lambs show colic, tympanites of the abomasum, and attempts at vomiting, though unfortunately these are often overlooked. The quantity of wool found in the abomasum and intestine on post-mortem examination may be considerable, in relation to the size of the digestive compartments. Death results from intestinal obstruction, exactly as in the case of calves.
These aberrations of appetite in lambs have been considered as due to the want of sufficient mineral salts in the mother’s milk; and it has been stated that the lambs practise this habit because of the laxative result of the fat contained in the wool swallowed. The explanation seems very logical, though it is by no means perfectly proved. It is certain that this habit becomes particularly common after years in which forage has been scarce and among flocks in bad bodily condition. The force of example also plays a certain part, and animals probably imitate one another, and so acquire the disease. This explains the importance of early segregation.
Diagnosis. The diagnosis of depraved appetite, pica, or the licking habit presents no difficulty; but it can only be arrived at by the cowman or shepherd, for the symptoms can only be detected by continued watching.
The diagnosis of pyloric or intestinal obstruction is very difficult in the absence of information. It becomes easy after the first post-mortem examination has been made.
Prognosis. The prognosis is grave. In calves, obstruction of the bowel by hair balls inevitably causes death, and in sucking lambs the mortality may be high: as much as 15 per cent. to 20 per cent. according to the observations of several observers. The mortality occurs about the age of six weeks to two months, whilst the licking habit may begin towards the end of the second week.
Treatment. Prophylaxis demands that the mothers (whether cows or ewes) be well fed. An excellent precaution consists in adding to the food a sufficient quantity of salt and of phosphate of lime (2 drams to 2½ drams of each). This treatment of the mothers is necessary as soon as the tendency to licking becomes manifest.