INFLAMMATION OF SUBSTANCE OF THE CORD 259 



in the hind fetlocks. Later it may become completely para- 

 lyzed behind the point of lesion. Horses may therefore 

 assume a sitting posture; cattle and small animals may drag 

 the hind parts. The skin and tendon reflexes may be exag- 

 gerated, especially if the myelitis has developed gradually 

 and the paralysis be of spastic type; or, on the other hand, 

 they may be greatly diminished, the muscles involved lose 

 tone, become flabby, and no longer contract. The bladder, 

 rectum, and tail eventually become paralyzed, leading to 

 incontinence of urine and feces and the development of a 

 limp tail. Provided the animal live long enough there usually 

 later develops atrophy of groups of muscles. Edema of the 

 skin and diffuse sweating have also been noted. 



Disseminated Myelitis. — ^This should be regarded more as a 

 multiple of the transverse type than as a separate disease. It 

 is very rare in animals. Depending upon the seat, size, and 

 number of inflammatory foci the symptoms vary. In some 

 instances they are identical with transverse myelitis. A 

 diagnosis is only possible when the patient manifests a cir- 

 cumscribed motor and sensory paralysis which may be con- 

 fined to one hind limb or to certain groups of muscles. Not 

 infrequently the muscles involved may show rhythmic twitch- 

 ings or contractions. In the horses a string-halt-like move- 

 ment of a limb has been noted. In the dog a desire to gnaw 

 at a part until it became mutilated has been observed. 



Diffuse Myelitis. — This is sometimes spoken of as ascend- 

 ing or descending myelitis. It is characterized by progressive 

 paralysis, motor and sensory, usually beginning in the hind 

 limbs, croup and tail and gradually involving the whole of 

 the body as the paralysis progresses anteriorly. Conversely 

 it may begin anteriorly and spread toward the tail. 



Course and Prognosis. — ^The course depends upon the seat 

 and the rapidity of extension of the inflammation. Trans- 

 verse and diffuse myelitis usually end fatally in a short time 

 while disseminated myelitis may last for months. Death 

 usually results from septicemia (decubitus), inflammation of 

 the paralyzed bladder and bowel, or in some cases from 

 respiratory arrest. Recovery is very rare, 



Digitized by Microsoft® 



