142 DISEASES OF THE HORSE. 
even though the feeding is high, and the attack is usually precipi- 
tated by taking the horse from the stable and subjecting it to exer- 
_ cise or work. The poisoning is not present when taken from the 
stable, as the horse is likely to be noticeably lively and spirited, but 
he will usually succumb under the first hundred yards or half mile 
of exercise. It seems as if the aspiratory power of the chest under 
the sudden exertion and accelerated breathing speedily drew from 
- the gorged liver and abdominal veins (portal) the accumulated store 
of nitrogenous matter in an imperfectly oxidized or elaborated condi- 
tion, and as if the blood, surcharged with these materials, were un- 
able to maintain the healthy functions of the nerve centers and 
muscles. It has been noticed rather more frequently in mares than 
horses, attributable, perhaps, to the nervous excitement attendant 
on heat, and to the fact that the unmutilated mare is naturally more 
excitable than the docile gelding. 
Ligniéres has found in hemoglobinuria a streptococcus which pro- 
duced nephritis, bloody urine, and paraplegia in experimental ani- 
mals, including horses. 
Symptons.—In the milder forms this affection may appear as a 
lameness in one limb, from indefinite cause, succeeding to some sud- 
den exertion and attended by a dusky-brown color of the membranes 
of the eye and nose and some wincing when the last ribs are struck. 
The severe forms come on after one or two days of rest on a full 
ration, when the animal has been taken out and driven one hundred 
paces or more. The fire and life with which he had left the stable 
suddenly give place to dullness and oppression, as shown in heaving 
flanks, dilated nostrils, pinched face, perspiring skin, and trembling 
body. The muscles of the loins or haunch become swelled and rigid, 
the subject moves stiffly or unsteadily, crouches behind, the limbs 
being carried semiflexed, and he soon drops, unable to support him- 
self. When down, the body and limbs are moved convulsively, but 
there is no power of coordination of movement in the muscles. The 
pulse and breathing are accelerated, the eyes red with a tinge of 
brown, and the urine, if passed, is seen to be highly colored, dark 
brown, red, or black, but it contains neither blood clots nor globules. 
The color is mainly due to hemoglobin and other imperfectly elabo- 
rated constituents of the blood. 
It may end fatally in a few hours or days, or a recovery may ensue, 
which is usually more speedy and perfect if it has set in at an early 
stage. In the late and tardy recoveries a partial paralysis of the 
hind limbs may last for months. A frequent sequel of these tardy 
cases is an extensive wasting of the muscles leading up from the 
front of the stifle (those supplied by the crural nerve) and a com- 
plete inability to stand. 
