Etiology. 889 



of the spinal cord, produced by cold and by rich feeding. According 

 to the hypothesis of Frohner the metabolism of the muscles is supposed 

 to be increased to such an extent by the very intense irritation of 

 the cold on the sensitiive nerves of the skin, that it causes the con- 

 tractile muscle substance to break down, and consequently muscle color- 

 ing matter, v^hieh is identical with the hemoglobin passes into the blood 

 circulation, and is eliminated by the kidneys. 



Various authors assert an infectious origin of paralytic hemo- 

 globinemia. Thus Cadiot believes in the possibility of an infection 

 through the intestinal canal, while Cadeae considers a streptococcus 

 infection probable. Lignieres found Gram-positive streptococci in the 

 subarachnoid fluid of the medulla, sometimes also in the kidneys, the 

 inoculation of which into mice produced a red discoloration of the 

 urine and increase of the reflex irritability; a horse which received 

 300 cc. of the culture intravenously could no longer get up from the 

 sixth day on, and albumen was demonstrated in its urine. In contrast 

 to this Nowak & Hartel also found the streptococci, but could produce 

 no disease with them; experiments carried out with the filtrates of 

 the intestinal contents of affected animals were also negative. 



Schlegel accepts as the cause of the disease the streptococcus 

 melanogenes described by him, and identified the paralytic hemo- 

 globinemia with the streptococcus of septicemia which is manifested 

 by a paralytic weakness of the hind parts (enzootic spinal meningitis, 

 see Vol. II). 



Hutyra & Marek believe it best to hold to the hypothesis 

 of an auto-intoxication. According to their belief they claim 

 to be justified in assuming that during the function of pre- 

 viously rested muscles or in muscles which have worked to 

 excessive exertion, some substance is formed which exerts a 

 toxic action and which produces a degeneration of the muscle 

 fibers and an elimination of the blood-coloring matter from 

 the blood corpuscles. This process occurs either while the blood 

 passes through the affected muscles, or at a later stage, when 

 the blood circulates in other organs. During rest and rich 

 feeding the suspected toxin-forming faculty of the muscles 

 may increase. It must probably be attributed to the last-named 

 condition that heavy, phlegmatic horses, which, as a matter 

 of fact relax their muscles much more completely during rest 

 than horses of a livelier temperament, and young colts become 

 affected more frequently; as a matter of fact colts are not 

 used at all for severe muscular work. By the sudden action of 

 cold the influence of the muscular functions could evidently be 

 increased up to a certain extent, as the irritation of the cold 

 stimulates the metabolism of the muscles (heat regulation). 

 Of what nature however the suspected poisonous substance 

 may be which develops during the muscular functions could 

 only be determined by suitable investigations and experiments ; 

 simple theoretical deliberations do not lead to results. 



Dispensing with detailed criticism of the above described hypotheses, 

 only the more important factors in favor of the myogenic auto- 

 intoxication will be brought out. The disease has, up to the present 



