SHEEP DISEASES

Wanganui Chronicle, Volume 73, Issue 424, 15 November 1930, Page 22 (Supplement)

SHEEP DISEASES

CASEOUS LYMPHADENITIS

NECESSARY PRECAUTIONS AT SHEARING TIME.

Caseous lymphadenitis, which rarely affects the general health of sheep and lambs but is of great importance in connection with vur meat export trade «ee iug that all affected carcasses have to be treated a» '‘rejects,” is one which is capable of being greatly reduced as regards the number of animals affected by it, and possible stamped out altogether on farms where it exists, if all possible precautions to prevent its spread are taken and efficiently carried r ut, states a circular issued by the Livestock Divis on of the Department of Agriculture. The Livestock Division of the Department has made a practice, when affected sheep or lambs are found by Inspectors at Freezing Works or abattoirs, of ascertaining the property from whence they came, and directly advising the owners of the fact and advising them as to the methods to be adopted for dealing with the trouble. Leaflets have also been issued broadcast. A great deal of valuable preventive work can be done at shearing an J crutching times as there can be no doubt that infection of wounds made, during shearing and crutching is one of the main methods by which the disease is spread. The disease is characterised by :he enlargement of lymphatic glands (kernels) in whicn abscess formation occu-s. resulting in the glands being practically converted into abscesses containing a creamy greenish coloured material. The abscesses frequently burst an their own accord and the matter exuocs on to ♦he surrounding wool and clings to it. Then, in shearing, the shears pick up the infection from this contaminated wool and each wound made afterwards can be automatically infected by the shears. A very probable additional method of infection is by dust or soil from sheep-yards getting on to newly made shear wounds, as the soil of yards is likely to carry infection on farms where this trouble exists, and it is quite possible that adjacent holding paddocks may also be infected.

Hence, it is a wise and desirable pr* caution to saturate the soil of the yards with a strong antiseptic solution—say one part of non-poisonous sheep dip to twenty parts of water. Holding paddocks might be ploughed and resown, and the shearing shed should be well washed down with a solution of nonpoisonous sheep dip before shearing commences. Apart from this much valv able and necessary and preventive won’ can be done at shearing tinfo.

Research work has been going on at the Wallaceville Laboratory where a small flock of affected sheep is being kept, and the latest knowledge obtained indicates that the following methods ought to be adopted:— (1) When sheep have been mustered for shearing, examine each sheep carefully for the presence of enlarged glands or ruptured abscesses, and set aside all those in which enlarged glands are detected. These sheep should be kept back and not shorn until all the rest of the flock has been shorn. In shearing them special care should be taken to apply disinfectant to all wounds inflicted. They should preferably be blade shorn, and the shears should be frequently dipped in an antiseptic fluid. One part of non-poisonous dip in thirty of water, or, alternatively, kerosene alone would answer this purpose. (The method of detecting affected sheep before shearing is described below). (2) Carfully disinfect, every wound made during the shearing of the apparently affected sheep, as well as those on affected ones. This can be done by using either—(a) A one-in-thirty solution in water of non-poisonous dip, or—(b) Equal parts of tincture of iodine and water. Tar is in common use and is good from the disinfectant viewpoint. It, however, clings to the skin, and later, to the growing wool, and is liable to thereby depreciate the wool from the manufacturers’ standpoint. •Shear blades should be cleaned ana disinfected frequently. This is easily done with blade shears, but owing to the oily accumulation liable to be present upon them, machine shears arc not so easily disinfected.

In order to detect the presence of glands enlarged through lympdadenitia infection, each sheep must be examined carefully at the points where the infected glands are almost invariably found. These points arc at the front of each shoulder and in the fold of each flank. They can be easily found, though the shoulder glands are a little below the surface of the skin. Not only must enlarged glands be sought by careful handling, but the skin and wool at these parts must be examined in order to detect the scars left by ruptured gland abscesses and collections of matter in the wool derived from these ruptured abscesses. In view of the close approach of the shearing season it is sincerely hoped that all sheepowners will carefully .- ct on the advice given above.