CHRONIC MYEI^ITIS. SCLEROSIS. 



Sequel to acute. Result of sprains and spinal injuries. Symptoms : pa- 

 resis on exertion, lameness in one or more limbs, knuckling, circumductive 

 movement of feet, uncertain planting, dropping, worse if blinded, phe- 

 nomena progrressive. Lesions : sclerosis of cord ; absorption of nerve cells 

 and fibres, in gray horns, and columns, superior, lateral and inferior, cord, 

 altered in color, unduly firm, in points softening. Stains deeply in car- 

 mine, lightly in osmic acid or hsematoxylin. Meninges thickened, nerve 

 roots atrophied. Diagnosis : previous acute myelitis ; later muscular weak- 

 ness, and paresis, under exercise : from embolism. Treatment : hopeless if 

 advanced ; progress delayed only. Good hygiene; tonics, open air, gentle 

 exercise, pure water, grooming, succulent pasture, nourishing food, alka- 

 lines, common salt, phosphates. 



Cases of this kind have not been satisfactorily diagnosed, and 

 as a rule domestic animals affected with partial paralysis are 

 rarely allowed to live in a condition in which they are offensive 

 to themselves and owners, a source of constant expense with 

 Uttle or no hope of recovery nor profit. Again, in the case of 

 the large mammals, the prolonged recumbency and the low grade 

 of nutrition in the semi-paralyzed parts, usually entail unhealthy 

 sores and septic poisoning which sooner or later prove fatal. It 

 is only, therefore, in the slighter cases, in which a fair measure 

 of control over the limbs remains, that these cases are likely to 

 survive. Trasbot suggests that many cases which pass for lum- 

 bar sprains are really chronic myelitis and on careful examination 

 will show spinal sclerosis. 



Causes. These are largely speculative, yet doubtless the same 

 causes which determine the acute form, will produce the chronic 

 when acting with less force and greater persistency. The lesions 

 that are left after an acute attack are calculated to keep up a 

 measure of vascular and trophic disorder which will be found 

 associated with more or less sclerosis. 



Symptoms. In "Weber's case in the horse (Recueil de Med. 

 Vet., 1884, p. 432) the advance was slow, so that for nearly a 

 year the manifestations were not diagnostic. At first there was 

 weakness of the hind limbs when worked to fatigue. Perfect 

 rest led to improvement, and work, to aggravation which became 

 steadily worse and worse. For a length of time the horse main- 

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