Prognosis. Mortality. Mortality varies much with the severity of the special outbreak and the conditions of life, favorable or otherwise, in which the flock is placed. In the milder forms the mortality may not exceed seven per cent, while in the more violent the whole flock almost may perish. A fatality of 20 to 30 per cent is the general average. Yet the inoculated form kills but 2 per cent.
If at the outset there is great weakness and prostration, complete anorexia and high fever, the prospect is discouraging. If the fever is moderate and strength and appetite retained, the case is very hopeful. On its first advent into a new country it causes a far greater mortality than after it has been long domiciled there, and frequent outbreaks have killed off the more susceptible strains of blood. Again very hot weather, or, still more, the prevalence of cold, drenching rains aggravates an outbreak and greatly encreases the fatality.
The loss is not to be measured by the deaths alone. The failure of the crop of lambs, through abortion, the shedding of wool, the loss of sight, hearing, hoofs, digits, flesh, stamina, etc, render recovery far from desirable, in the worst cases, as the animal fails to thrive or pay for its keep. On the contrary it is immune from any future attack, and if left in a thrifty condition it becomes especially valuable in a district where sheeppox prevails.
Treatment. Once established in the system the disease will follow its regular course, through all its stages. Yet we can, by dieting, pure air, cleanliness, shelter and even by medicinal measures, do much to render that course a safe one. Cool sheds, pure air, clean floor, dry clean litter and shelter from rain are above all important. The sheep may be separated in different enclosures in small lots of 5 or 6 to prevent crowding, heating, and excitement, and in any case the infected should be removed from the noninfected, and even from each other to avoid infection and reinfection. This is especially requisite in hot weather.
For the strong and vigorous, a diet of sliced roots and meal (oat, bran, linseed, barley, wheat middlings) is good, while for the weak, gruels of oat meal, barley meal, linseed meal, or the same agents dry, may be given. Powdered saltpeter may be given in this (1 oz. to 8 or 10 sheep) and common salt allowed to be licked at will. Drinking water may be given pure, or slightly acidulated with sulphuric or hydrochloric acid, or hyposulphite or bisulphite of soda may be used as a substitute for the latter. The bowels are usually costive, and may be relieved at first by 3 ozs. of sodic sulphate, and later, if need be, by soapy injections. Often during the course of the disease a sudden access of fever may be cut short by a mild laxative, if that is not contra-indicated by existing diarrhœa.
Avoid giving heating agents to bring out the eruption. The severity of any case and the danger of complex infection are usually in ratio with the extent of the eruption.
Lotions of hyposulphite of soda may be applied to the affected parts from the first, and even weak lotions of chloride of zinc after the maturation of the pustules. For the eyes, nose and mouth antiseptic lotions may be called for.
In the advanced stages, in weak subjects, tonics and stimulants may prove useful. To the mineral acid, quinine (10 grain doses) or gentian (drachm doses) or other bitter may be added for valuable stock.
Treatment is only permissible in the case of very valuable animals and when they are surrounded with the most perfect antiseptic precautions, to prevent the escape of the infection.
Prevention. As in all dangerous infections this must be the preëminent object, and when a new country has been invaded by the disease, no sentiment nor alleged value of affected or exposed animals should be made the warrant for treatment, nor stand in the way of the extinction of the plague by the most rigorous measures. The recovery of an individual flock is never to be put in the balance with the danger to which other flocks are thereby exposed. To avoid smuggling away of exposed animals, and consequent spread of the disease, the loss should be met by the commonwealth and no foolish idea of administrative economy, should tempt a stock owner to endanger the flocks of a whole nation.