INFLAMMATION OF THE SPINAL CORD AND MEMBRANES 247 



sexual organs is an exciting cause, but this is not admitted by all ob- 

 servers. Chronic inflammation of the cord is indicated by disturbances of 

 mobility, the animal is easily tired on very slight exertion, shows a want 

 of coordination in walking, great difficulty in rising after lying down for 

 some time, regular or irregular twitching of the muscles in the affected 

 extremities, or complete paralysis of the hind quarters and in very rare 

 instances of the anterior limbs, more or less disturbance of the sphincters, 

 and gradual atrophy of the affiected muscles. The appetite is invariably 

 good and there is no rise of temperature. 



Pachymeningitis spinalis ossificans, that peculiar disease indicated by 

 a gradual ossification of the spinal membranes, is not at all uncommon in 



Fi3. 95. — ParalysLs of the cord. 



dogs of an advanced age. This disease consists of a gradual inflamma- 

 tory process of the dura mater, in which that tissue gradually becomes 

 filled with numerous irregular or massed collections of tolerably firm 

 bony scales, situated on the ventral surface of the tissue, particularly 

 in the region of the cervical and lumbar regions of the cord. The 

 whole dura mater may become converted into a hard bony tube, and in 

 exertion of the body the roots of the nerves may be torn from the spine. 

 The ossific hardening of the dura may be present for a long time be- 

 fore any actual clinical symptoms are present (Cadeac) and are gener- 

 ally produced by laceration of the sensory nerve fibres, by violent or 

 unusual movements, or movements in a certain direction of the spine. The 

 voluntary movements of the animal are cautious, stiff, or stilty, either on 

 walking about, lying down, getting up or climbing up stairs; the latter he 

 may refuse to do, and on forcibly bending the spinal column the animal 



