674 
PARALYSIS OF THE HIND LIMB. 
muscles attached to the patella, and in a similar degree, a condition 
scarcely to be expected in a purely muscular disease. The sudden 
onset and equally rapid disappearance of the disease, as well as the 
total want of inflammatory symptoms, support this view. Where 
disturbance of sensation on the inner surface of the thigh exists, there 
can be little doubt of the nature of the disease. Goubaux divided the 
neive expeiimentally high up in the thigh, between the vastus internus 
and lectus femoris, and thus obtained all the symptoms of muscular 
paralysis peculiar to hemoglobinuria. Other conditions, like psoas 
abscess, tumour formation, hemorrhage, &c., may also destroy the 
function of this nerve temporarily or permanently. 
Though post-mortem examination sometimes shows the rectus and 
vasti muscles in a marked state of fatty degeneration after this disease, 
that fact m no way proves the condition to have been myopathic lame¬ 
ness, as has been suggested. 
Symptoms. Weight cannot be placed on the limb, because it is 
impossible to fix the stifle-joint, a necessary preliminary to walking. 
Attempts to sustain the body on the affected limb are followed by 
flexion of all the joints, including the phalanges. The stifle-joint is 
not completely extended on the ilium, and the skin on the inner surface 
of the thigh loses its sensibility. At a later stage the quadriceps 
femoris muscle atrophies; its loss of function is immediately seen 
when the animal moves, and may be detected by local examination. 
In incomplete crural paralysis the body sinks towards the affected 
side, whilst all the joints become somewhat flexed (fig. 256), the last 
period of the stride being consequently shortened. Animals suffering 
from this disease learn to move better, however, in time, the ah- and 
ad- ductors of the limb co-operating to fix the stifle-joint. This action 
is easily detected when the animal is walked very slowly past the 
observer: it is then seen that the upper end of the tibia is not only 
drawn backwards and upwards, but the patella is fixed on the condyles 
of the femur. The last symptom to disappear in convalescence is the 
upright position of the os suffraginis, a consequence of incomplete action 
of the rectus and vasti. 
Paralysis of the crural nerve or of the above muscles may be mistaken 
both for muscular rupture and for lateral luxation of the patella (vide be. cit) 
Kuptures in the various extensors of the patella have been seen by numbers 
oi practitioners. Delwart saw three cases of rupture of the rectus femoris in 
the horse, all caused by slipping or falling; two proved incurable. The 
symptoms resembled those of the above-described paralysis Not infre 
quent y a depression could be detected in the muscle. Post-mortem examina- 
tion showed the muscles to be pale, as though boiled, their fasciculi shredded 
out and partly separated. 
Schmidt describes rupture of the vastus externus. A horse had trodden in 
a deep rut, and, the ground being frozen, was unable to withdraw its foot 
