196 Journal of Agriculture. [8 April, 1908 



and open through the skin generall)- at a part higher than the seat of the 

 imprisoned matter. Fro.n these openings a little matter is gradually dis- 

 charged, but the bulk of it cannot get away (it cannot run uphill), and so 

 the inflammation continues and spreads beyond the original seat until, 

 perhaps, the spines of the back bone are implicated, in which case there 

 is little hope of recovery, except in the hands of a really skilful veterinary 

 operator. 



Causes. — Fistulas are very common in Australia — so common that I 

 have myself had to operate on as many as half-a-dozen cases in a single 

 forenoon. I have seen three horses affected simultaneously on one hold- 

 ing, and these included all the horses that were kept. I know of a con- 

 tractor keeping between fifty and sixty horses who had fourteen affected 

 all at one time, and I have heard it stated that the disease was contagious. 

 From the nature of the disease it is evident that this view is altogether 

 erroneous. It is simply founded on the knowledge that a number of 

 horses on the same farm or in the same paddock are simultaneously af- 

 fected, and the fact is lost sight of that what will act as the cause in one 

 ( ase will likewise act in others. 



Cases having their origin in the uneMual pressure or pinch of a badly- 

 fitting saddle, are bv no' means uncommon, but the situation of a large 

 luimber of cases, especially in draught honses is slightly to the front of the 

 withers, at the setting on of the neck tO' the shoulder ; just at the place, 

 in fact, against which the top of the collar is pressed when the horse 

 throws his weight into it. If the collar is closed at the top, and especi- 

 ally if it is well made to fit the horse, the pressure on the withers and 

 top of the shoulders is equally distributed, and no particular spot is 

 bruised or pinched. The open-topped collar is however in almost univer- 

 sal use in Australia, and, if it does not happen to be buckled up tightly, 

 or if the hor.se has improved in condition, lendering the letting out of a 

 hole or two necessary, there is a part, directly at the top from which the 

 mane grows, that receives no pressure at all. As the horse pulls, the 

 two upper extremities of the padded portion of the collar on each side are 

 of a necessity especially when the traces are attached high up on the 

 hames, pressed backwards, downwards, and inwards, exactly at that spot 

 where the first sign (swelling) of fistula in this situation appears — viz., 

 on each side of the backbone, just in front of the highest point of the 

 withers. Steady pressure of this sort may only be productive of passing 

 effect; but a jerky pressure or ])inch occasioned when the road is rough, 

 the load awkward, or weight not properly adjusted, will .sooner or later 

 result in a bruise which may be so severe as to give rise to an abscess — an 

 abscess at this part generally resulting in fistula. 



The most prolific cause however is tO' be found in the stumpy and 

 stony condition of a large number of Australian paddocks, and also in 

 the hard nature of their surfaces in the summer time. At all events, pad- 

 docked horses are very liable to fi.stulous withers, whether it be from 

 rolling on stumps of trees or stones, or on the hard ground (especially 

 in hoTses with high withers), or from injury to the withers 

 by the outstanding low branches of trees when grazing in bush 

 l^addocks, or from the bite or pinch of another hor.se when in 

 the act of scratching each other, or keeping off flies or other irritating 

 insects. It is ]x>ssib]e, too, or even probable, that Australian horses are, 

 on account of their liability to general disease of bones, somewhat con- 

 stitutionally predisposed to fistula, for the chipping off of a small frag- 

 ment of one of the bony spines of the withers would excite sufficient in- 

 flammation to produce a fistula of the wor.st order. 



