LAMENESS IN HORSES 
303 
to be the same lesion, under the head of “ RELAXATION AND 
Straining of the Master Sinew more properly, in accord- 
ance with the present state of veterinary science, denominated 
Rupture of the Gastrocnemius Muscle. 
A 20, black troop-horse, four years of age, in the act of longing 
early in the morning of the 16th of May, [843, fell forward upon 
his head and knees, with his hind limbs left sprawling in the fall 
in an extended position behind him. He lay for a couple of seconds, 
then rose up, and walked twice round the longe. Finding, how- 
ever, that he had lamed himself in one of his legs, the rough-rider, 
who had been longing him, returned him to his stable. At 
nine o’clock A.M. I had him led out in hand. He walked tolerably 
well ; but when he came to trot, or even to turn, there was mani- 
fest a giving way of the off hind leg, owing, to appearance, to a 
want of contraction in the muscles bracing the tendo Achillis. 
This induced me at once to suppose there must have happened 
some rupture or laceration of the fibres of the gastrocnemius mus- 
cle ; and yet my most careful examinations failed to detect any 
defalcation or defect thereabouts. In fact, I could make out nothing 
more than unusual mobility of limb. I prescribed a high-heeled 
shoe, quietude, a warm bath, and a dose of physic. 
On the 18th May — two days after the accident — the fore part 
of the hock was observed to be considerably swollen ; and the 
swelling was tense and warm to the feel, as though some sprain of 
the part had taken place. In another two days this tumefaction 
had begun to subside, so that by the 25lh — a week from the acci- 
dent happening — the hock was well again. 
The next time 1 saw the horse walk out — which was on the 
2d of June — I could not perceive any alteration in the action of the 
limb, either for better or worse. There was evident the same 
laxness or looseness in the tendo Achillis; the same instability and 
rolling movement in the limb as he walked along; nay, the latter 
was very observable in the stall even every time the horse’s hind 
quarters were turned from side to side : there was manifest want of 
bracing of the tendon in question. Instead of retaining that well- 
known tensity and firmness of feel which it possesses so long as 
the foot rests upon the ground, the tendon becomes so slack that it 
absolutely wrinkles, or serpentines in its course to the hock, the 
moment the limb is lifted off the ground. No other view, in my 
mind, could be taken of the case than that expressed here in its 
heading. It will be recollected that the two gastrocnemii muscles 
cross each other in their course from the back of the stifle to the 
hock, and that, in their composition, fleshy fibres are interlaced 
