In the case of the mare the proprietor is under strong temptation to ignore the sanitary measure under consideration. When her eyes fail, her value in the public market is greatly depreciated, yet she can yearly produce a foal, which is finely developed and will bring a high price if sold young, before it has been attacked by the disease. Hence the great importance, at least in the case of all horses which are not intended for exclusive use on the race course, that a law shall be strictly enforced which will put an absolute limit to the breeding from horses that have been affected with recurrent ophthalmia.
Blows, dust, sand, smoke, irritant gases, fierce light, and all sources of irritation must be avoided as in other eye diseases.
Treatment. Radical treatment for the disease is far from generally satisfactory. Too often the affected animal is still in the environment which has tended strongly to its development, and it is impossible to secure a satisfactory change. As far as possible, however, every available sanitary measure mentioned under the head of prevention should be enjoined, and largely in proportion to the thoroughness of such measures, and the slightness and recentness of the attack will be the hope of a successful treatment.
In some instances in which there appears to be a rheumatic complication, the employment of anti-rheumatic agents have proved of essential value. Powdered colchicum corms may be given twice a day in doses of 1 scruple, combined with salicylate of soda, salicylic acid, or salicin in 2 drachm doses. To these may be added bicarbonate of soda or of potash in drachm doses.
In cases attended with marked fever, hyperthermia and anorexia, antiphlogistic treatment may be desirable, but with the primary consideration that it must not be materially depleting, nor calculated to induce debility or atony. A laxative dose of aloes will sometimes benefit, but should be avoided in the absence of manifest fever. Two or three ounces of Glauber salts, twice a day, will effect the same purpose with less danger. Or saltpeter or other cooling diuretic may be given daily. In most cases bitters may be added with advantage.
In severe cases, rest is essential until the violence of the inflammation shall have abated, and a dark stall or a cloth to obscure the light is equally important.
Trasbot advises bleeding from the jugular, but such a depleting measure finds little support in England or America. Local bleeding from the angular vein of the eye or by leeching or cupping is not open to the same objection.
Counter-irritants are, however, more suitable. A stout silk thread may be inserted above the lower end of the zygomatic ridge and bathed and moved daily to prevent the lodgment of pus. Or a blister of cantharides or biniodide of mercury may be rubbed in on an area as large as a silver dollar in the same situation.
In all cases a strong solution of atropia sulphate (2 per cent.) may be instilled into the eye once or twice daily. Or a mixture of atropia and cocaine (1 per cent. of each) will give even greater relief. If to these is added 1 per cent. of pyoktannin we get a collyrium which is at once anæsthetic, midriatic and antiseptic. This is often of material value. Vigezzi advises a mercuric chloride lotion (1 ∶ 1000) as a collyrium, and for injection in the submucosa.
If the local inflammation runs high an astringent lotion may be applied externally on a soft rag hung over the eye and kept constantly wet. Sugar of lead or acetate of zinc may form the basis of such lotion with a little atropia or morphia added.