The diagnosis is difficult, particularly on the first occasion of seeing the disease, and especially if this is of an enzootic character. The practitioner may also have some hesitation in diagnosing isolated cases in regions where the disease seldom occurs.
Otherwise, diagnosis is usually easy, as soon as lameness or synovitis, or arthritis of the lower regions of the limbs appears. Only in isolated cases are the lesions likely to be mistaken for accidental injuries, and it is also fairly easy to differentiate them from the localised lesions of rheumatism. The latter disease seems more frequently to attack the upper joints of the limbs, and is often accompanied by intense fever and cardiac disturbance.
Prognosis. In a general sense the disease is very grave, because it appears as an enzootic, and, in dry years and those during which there is a scarcity of forage, inflicts enormous losses on the breeders of certain countries. When advice is sought towards the end of the second phase of the disease the prognosis is therefore very grave. Under such circumstances it is often better to slaughter rather than to treat, provided that the affected animals, like cows, pigs, or goats are still of some value.
The prognosis is much more hopeful if treatment is attempted at an early stage, when improved diet and the use of suitable drugs sometimes lead to recovery.
Treatment. We know that in the Middle Ages this disease was often treated by the administration of crushed bones, and even at the present day ground bones are frequently recommended. Treatment must be subordinated to proper feeding, no system of medication being of any value whatever unless the food is suitable.
Germain states that imported horses in Cochin-China recover if simply returned to their former diet, i.e. to cereals and forage obtained from France or Algeria. Cantiget shows that such improvements in cultivation as the free distribution of superphosphate manures on impoverished soils modify the chemical composition of the forage, and render it capable of building up and sustaining the organism and bony tissues; treatment should therefore be essentially prophylactic in character.
Animals suffering from osseous cachexia should be fed on cereals and forage obtained from rich districts where the disease has never occurred; but, as in times of scarcity questions of expense almost always receive first consideration, it may be necessary to substitute bran for such products, or give oats, maize, beans, rice, and oil or cotton cake, etc., all of which can be obtained commercially, and are of sufficient nutritive richness. It is often advantageous to give such food cooked and slightly salted.
Commercial ground bones and calcium phosphate (bi- or tri-basic), in doses of 1 ounce per day for oxen and 1¼ to 2 drachms for pigs or goats, have given excellent results in the hands of most practitioners. Some recommend the addition of iron salts or bitter tonics like gentian or nux vomica in doses of 2½ drachms per day for a full-grown ox.
Law declares that the treatment should be varied “with the predominance of the causes, essential or accessory.... Green clover, alfalfa, and other leguminous products, ground oats, beans, peas, linseed or rape cake ... and vetches may be especially recommended.... The free access to common salt and a liberal supply of bone meal are helpful.... Apomorphia is especially valuable in correcting the perverted appetite and stimulating digestion. A change of pasture is always advisable. In all cases where possible the water should be changed as well as the food. Attention to the housing, grooming, and general care of the animals should not be neglected. Finally, every drain upon the system should be lessened or stopped. The milk may be dried up, and the animal should not be bred.”
Meat meal also renders good service, but the use of cod liver oil, suggested by Zundel, is too expensive, and phosphorised oil is too dangerous to be adopted in ordinary treatment.