FOOT-ROT IN SHEEP.

Otago Witness, Issue 3325, 5 December 1917, Page 10

FOOT-ROT IN SHEEP.

In our previous issue attention was drawn to foot-sore in sheep, in contradistinction to foot-rot of a contagious nature. The latter disease is quite different, and very much more troublesome to cope with successfully. It has been proved beyond a dotfbt that the virus or poison of the disease is infective; that is to say, the application of infected matter from diseased sheep to healthy animals may result in disease, and healthy sheep, if associated with diseased animals, may "catch"—if Ave may use the term —the disease. If the infective germs are present, it is not very material whether the sheep are on dry or wet pastures, although the latter may be generally deemed the worst. As the English Board of Agriculture points out in a leaflet .in the Live Stock Journal: "It is admitted by those who are acquainted with the diseases affecting the feet of sheep that in some cases of foot-rot, especially in the advanced cases, 1 the diseased conditions may be so similar in appearance to foot-sore that a differential diagnosis is very difficult; but by carefully considering all the circumstances, and by examining the fellow sheep, especially the more recent cases of disease, one will find that in foot-sore the trouble begins in the horn at the lower part of the foot. Contagious foot-rot is primarily a disease affecting the soft structures of the foot. Any diseased condition of the horn itself is secondary, and is brought about by the separation of the soft from the horny structures through the agency of micro-organisms and the fluids exuded. The disease spreads from sheep to sheep, causing much lameness, loss of flesh, and even death from emaciation. If the disease appears in a flock of in-lamb ewes it is a still more serious matter, as proper treatment cannot be carried out without danger, owing to the ju'egnant condition of the ewes. In such instances the disease persists until the lambing season commences, and often spreads rapidly to the new-born lambs. Apart from the adverse influence that wet seasons and clamp low-lying pastures may have upon the horny structures of the feet, grit and dirt may work their way into the cleft of the foot and produce a wound. If the soil is contaminated with the virus that produces foot-rot, the disease will soon appear among the flock. It may, however, attack sheep with apparently firm horn and well-trimmed feet." Lameness is usually the first symptom observed, and on examination of the affected foot a small, moist, unhealthy<-looking spot-like sore will probably be found between the toes. The part is inflamed, hot, and tender, and when it is manipulated the animal shows signs of pain. There is little or no appreciable swelling of the coronet at this stage. The disease spreads rapidly under the horny box, and if a little pressure be brought to bear on the inside of the foot a slight dirty, fcotid discharge will be observed oozing front the edge of the horn around the ulcerated spot. The di&oharg» is n-avec very great, but is always foui-smelling; in fact, the foetid smell is often detected before any gross lesions have been discovered. The disease progresses from above downwards, between the sensitive structures of the horn and the hoof. When the horn is pared away, the diseased parts are found bathed in the foetid discharge, and the greater portion of the foot may be involved. In protracted cases the foot may be greatly swollen, very tender, and hot. The upper part of the toe is widely separated, a«x4 the point 3 turn inward,giving the appearance of a club. Abscesses form in the soft tissues of the foot and around the coronet. One foot is usually affected at the outset, followed by two, three, or ail four feet, when the animals cannot get «bo\ifc for food, and may be seen feeding on their knees. These sheep sopn get very emaciated, and, if unattended, do not live for long. During hot weather the condition Is aggravated, and deaths are more numerous from the fact that the foetid discharge attracts flies, and maggots subsequently develop in the wounds. An affected animal may become fly-blown on every part of the fleece which has come in contact with the discharge, and under such circumstances it soon succumb?. With ordinary watchful care the disease can be checked in good time. All bought-in sheep should b& carefully scrutinised, and any sheep falling lame should be examined immediately. The following precautions are suggested as only wise where the contagious form of foot-rot is suspected : 1. The periodic inspection, examination, and trimming of over-grown feet is a practice to be recommended, and upon the slightest indication of disease affecting the skin between the toes the affected sheep should be isolated and treated, and the remainder put through a bath containing a foot-rot preparation.

2. In the case of sheep bought in a, market, or takon to a market and brought back, or any fresh arrivals, they should, whenever possible, be isolated and tho feet of each sheep examined. Isolation should be continued for three to four weeks, as disease might appear after an interval of two or three weeks, although tho sheep appeared apparently free from disease at tho time of arrival; or as a precautionary measure after examination the sheep should be put through one of tho specially constructed shallow baths containing one of the preparations for foot-rot, oh two or three occasions _ during the first week or 10 days after arrival and before mixing with the other stock.

3. The shepherd should always wash and disinfect his hands after examination _of the recently imported stock before attending to any of the old stock; and tho same remarks apply after the examination of any individual suspected case. 4. It is advisable" to afford contaminated pastures a- rest from sheep until a winter's frost has intervened.

5. Attention must be given to the sheep fold and other pens, "which should be thoroughly and effectually disinfected, and the manure and a few inches of the surface soil shoidd be removed and ploughed into the lancf.