690 Inflammation of the Spinal Cord. 



cause inflammation of the spinal cord as lias been frequently 

 demonstrated in encephalitis. In very rare cases there de- 

 velops simple tuberculous myelitis. It is remarkal)le that there 

 is scarcely any tendency to purulent myelitis in the case of 

 strangles. There are also other unknown causes. In a case 

 recorded by Dexler, a dog, eight years old, had got loose one 

 cold night a month and a half previously and was found the 

 next morning half numb. The dog showed symptoms of mye- 

 litis which were referred by Dexler to an infection of some 

 sort. The same author observed a case of hemorrhagic inflam- 

 mation involving the spinal cord as well as the brain in a 

 horse. Marek records two similar cases in dogs, and one in 

 a horse. Myelitis of unknown origin has been recorded in the 

 horse by Weber and Barrier, Lienaux and Hendricks, Le Calve, 

 Watson, and Savary. Hutyra & Marek have on one occasion 

 observed inflammation of the dorsal portion of the cord in 

 a horse used for the preparation of diphtheria serum. Ceni 

 and Besta produced chronic diffuse m^^elitis in a dog by feed- 

 ing it on maize contaminated with the aspergillus fumigatus. 

 The paralysis-like weakness observed in fowls by Wilke, and 

 described by him as anterior acute poliomyelitis was probably 

 a disease of the bones resembling rickets. 



Marek found a diffuse iuflanimatiou of the spinal cord in four dogs ex- 

 tending- over the greater part of the cord, and in all the cases there was extensive 

 hemorrhage and necrosis of the cord, but he was unable to discover the cause of 

 the condition. The possibility of its being distemper was excluded. In three of 

 the cases extensive hemorrhagic enteritis was found at the postmortem, but it re- 

 mained undecided whether the myelitis was a sequel to the enteritis or the enteritis 

 a complication of the myelitis. Brown & Ophiils observed four cases similar to 

 the above in dogs, but there was no enteritis. 



As already mentioned, inflammatory processes involving 

 the membranes frequently extend to the neighboring parts of 

 the cord. The same thing happens in epizootic cerel)ro-spinal 

 meningitis. On the other hand, diseases of the vertebrae and 

 surrounding tissues rarely extend to the cord. 



Some authors state that myelitis may be caused by cold or 

 over-exertion, but these can only be considered as predisposing 

 causes. Excessive use of animals for sexual purposes plays 

 no direct part in the production of the disease. 



Anatomical Changes. Macroscopic lesions are not always 

 present. In cases of distemper-myelitis there are no hemor- 

 rhages or very slight ones, and usually also no softening, con- 

 sequently the condition is often overlooked. In other cases, 

 the inflamed parts of the cord are obviously altered. In recent 

 cases they are softer, and in older cases, firmer. They are very 

 rarely thickened, but more frequently become thinner. After 

 section the substance of the cord generally runs out ; the differ- 

 ence in color between the gray and white sulistance is indis- 

 tinct, or there may l)e none. In acute cases the softened cord 



