FOOTROT IN SHEEP

New Zealand Herald, Volume LXXIII, Issue 22320, 18 January 1936, Page 22

FOOTROT IN SHEEP

STUDY OF THE CAUSE NEW THEORY ADVANCED ROLE OF MYSTERIOUS MICROBE . V , An officer o| tho Council of Scientific and Industrie! Research, Mr. W. I. B. Boveridgo, working at tho McMaster Animal Health Laboratory, Sydney University, has mado a discovery which may revolutionise all previous conceptions of tho causo and treatment of tho disease in sheep known as footrot. An unidentified inicrobo, designated for the present " Organism X," may bo responsible. Tho cause of footrot has eluded detection for several generations, and its control and euro lmvo presented a baffling problem to investigators in many parts of tho world. With tho correlation of' a hitherto unsuspected germ with the trouble, an attractive possibility of a cure is presented. Tho organism now thought responsible, having its natural habitat in animal tissue, is incapable of living apart from its host, as in tho soil, for any prolonged poriod, and so the treatment or elimination of affected sheep during summer may completely eradicate the disease from a property. Cause ol Contusion Much confusion about footrot derives from the description of several types of tho complaint. It seems likely that these variations are only different clinical manifestations of the same disease. The most prevalent appearance in Australia is characterised by the separation of the horn of the foot from the soft tissues, followed by certain amount of death of the _ tissues. Although authoritative opinion has agreed for some time that footrot is a contagious disease, differences of opinion exist about tho specific organism responsible. It seems probable that progress in the past has been impeded bv blaming a germ called bacillus necrophorus, usually abundantly present, but which is not the" primarily causal agent. In no experiment could Mr. Beveridge induce the disease in sheep by the use of this bacillus alone, and a series of tests showed that the disease was not a virus trouble. Nevertheless, ho transferred the disease to clean sheep by using infected material obtained from suffering animals. This liquid, as usual, showed the bacillus in predominance. The conclusion was then arrived at that a hidden, or, at least, an apparently insignificant germ was the real originator of the trouble. A careful microscopic study was made of diseased tissues variously stained and dyed to bring into prominence tho different germs associated with the condition. A glimpse was eventually caught of numerous minute filaments differing only very slightly in form from the übiquitous bacillus necrophorus. Subsequent examinations showed these filaments to be a distinct and separate organism. Review of Findings Further study of the motility of the germ indicated that it was propelled, not by mearig of the lashings of hairlike appendages, but by a rotation round its long axis. This suggested that the organism belonged to the big group termed Bpirochaetes, and not to the bacilli. Other investigators have previously identified a member of the former group with the trouble, but points of essential difference between tho two germs are apparent. Discussing these findings in practical terms, Mr. Beveridge said that the clinical manifestations of footrot generally disappeared during summer and recurred when conditions became favourable. ' Investigations of American workers indicated that the causal agent of the disease could not livo long in the soil. Although confirmation was required, it was probable that during tho summer, when the disease was in abevance, the infective agent persisted in the animal. During periods when there were no obvious cases of footrot in a flock, the infection might live in superficial lesions in the feet of some of the sheep, ready to spread throughout the flock when conditions were favourable.