DISEASE IN SHEEP

New Zealand Herald, Volume LXXV, Issue 23019, 22 April 1938, Page 16

DISEASE IN SHEEP

FACIAL ECZEMA INCREASES

FLOCKS BEING DECIMATED REVIEW OF THE CAUSES BY H.B.T. At the present time a large number of the North Island flocks are being literally decimated by what appears to be a combination of several troubles now classed under tho one heading of " facial eczema." Twenty or more years ago this disease was known as "bighead," "thick-ear," "j-ellows" and, perhaps, other titles as descriptive of various symptoms of the disease, but in those days a few sheep only were affected and a euro usually resulted from drenching with a stiff dose of Epsom or glauber salts, and smearing the sensitised skin of the face with raw linseed or olive oil (1 part), limewater (1 part), carbolic acid, k l per cent. These were shaken together to form a cream, or emulsion, and lampblack was added to give a deep black colour, which the harmful rays from the sun would not penetrate. "I? ape scald" in lambs, which resulted from feediug off rape which was not quite mature or "ripe," had much tho same symptoms, except thnt the back of the animal was also usually affected, so that tho wool came out and a hard scab was formed, often extending from shoulders to tail. To correct this scald trouble, when taken in time, a dose of 10 grains of calomel, followed 12 hours later with a loz. drench of Epsom salts dissolved in water, was most effective. But one hesitates to recommend sheepmen with large llocks which are affected to undertake the onerous job of drenching twice within a few hours when other remedies, efficacious in the past, have proved ineffective with the present form of the disease. Symptoms ol Trouble " Facial eczema," so-called, is apparently a combination of photosensitisation or " clover disease " and jaundice in a severe form, which, combined, produces what is known as "toxaemic jaundice."

The early symptoms aro that the ears and nose become itchy and tho sheep rub or scratch the head and seek shade. Tho parts become hot and inflamed. Tho ears, eyelids, lips and face become swollen and there'is a discharge from tho eyes, nose and lips. Tho ears also hang down and tho inner membrane of the eyelids becomes red and swollen, tho eyes sometimes being completely closed. The discharge from the eyes find nose is at first thin and watery, but is later like pus, while the nostrils are liable to become plugged with mucus, causing difficulty in breathing. There is every indication of severe fever in the affected parts, tho skin of which has a yellowish colour, due to the jaundiced condition of tho sheep. Under the skin of the head, and sometimes of the forelegs also, a yellow fluid collects. Later, this fluid oozes through tho skin, dries and forms crusts or scabs, yellow or brown in colour. The skin over tho affected parts may become so dry and hard as to appear like scorched leather. When this sloughs off, it leaves a raw, tender skin. In some cases the ears and lips may slough off. Losses through deaths of affected animals may total 50 to 75 per cent, and tho condition may last for a few days or for several weeks, depending on the weather conditions and consequent pasture growth.

Preventive Measures Tho immediate cause appears to bo a superabundance of quickly-growing clover and ryegrass, which, in hot weather,, and particularly soon after rain, contains substances which render white skin sensitive to certain types of tho sun's rays. In the process of digestion, the hydrochloric acid in the digestive juices acts upon tho chlorophyll and produces chlorophyllan in such quantity that the excretory organs cannot deal with it. When this is absorbed into the blood it is converted into phylloporphyrin, which then acts as a photodynamic substance in unpigmented skin exposed to the direct rays of tho sun. Black Blieep and black-faced sheep are not affected with the "facial eczema" symptoms, although they may become jaundiced as a result of an overloading of the system with toxins of which the liver, kidney and bowels cannot rid it. In devising • preventive measures against this disease, it must seriously be considered whether heavy and continuous top-dressing which encourage rapid ,and luxuriant growth of clover rye-grass to the exclusion of most other pastnro species, is not an important contributory cause of "facial eczema." It is certain that animals on coarser and less highly-nutritious - pastures and native grasses are not so susceptible to "facial .eczema" as those on ryegrassclover which has been heavily topdressed. Some farmers, indeed, claim that they have beon free, from tho trouble even on ryegrass paddocks which have not been recently topdressed. • Method ot Treatment

Assuming that over-manuring with phosphate has some influence in causing the disease, it is. probablo that it is not so much a superabundance of phospliatic manure as a comparative deficiency of other minerals and plant foods essential to healthy grass growth that creates an unbalanced and toxic diet. Such deficiencies would most probably be those which stimulate the " endocrincs" —or ductless glands—the duty of which is to secrete hormones, which activate the excretory organs. Such deficiencies would probably bo of mineral origin. The whole subject .of disease prevention bristles with difficulties, but results so far achieved in the prevention of many other diseases suggest that the first , line of research should be'in the direction of supplying to the soil and' stock minerals and plant foods found, from analysis, to bo deficient in the soil. The treatment recommended by an Australian authority, 11. A. Vernon, for " toxaemic jaundice." which is apparently identical with our "facial eczema," is to pick out all the affected sheep and remove to woolshed or plantation, away from direct sunlight. Move the "balance of the flock to a fresh paddock. Treat tlfe affected sheep by opening the swollen, parts to allow the oedematous fluid to escape. Flush out such incisions with a 2 per cent solution of permanganate of potash. Remove the mucus from the nostrils to permit free breathing, and remove the crusts from the skin and eyelids. Smear the affected parts with a mixture made by shaking equal parts of raw linseed oil and limewater together to form a cream. For removing the crusts from nose, skin and eyelids, use a cloth dipped in warm oil. A drench which is effectivo in correcting jaundice in sheep, such as calomel followed by Epsom salts, should be given. Or give the following: Aloes, 2 drachms; fluid extract rhubarb root, 1 drachmj warm water, 8 fluid ounces, followed in 24 hours with loz. Epsom salts, dissolved in water.