684 Ossify 



iiig luflanmiation of the Dura Mater of the Spinal Cord. 



and the conductivity of the sensory and motor nerves is not 

 destroyed there are active reflexes. In view of the fact that 

 the process of ossification rarely extends backwards from the 

 himbar region to any marked degree, the reflexes in that por- 

 tion of the hind quarters are often exaggerated in the later 

 stages of the disease. 



Incontinence of urine and involuntary discharge of feces is 

 rarely seen in cases where the nerve roots of the bladder and 

 rectum are involved, but somewhat more frequently if the cau- 

 dal portion of the cord be compressed. Retention of both 

 urine and feces is far more often seen. The digestive func- 

 tions remain undisturbed for a long time, but finally nutrition 

 suffers, and the animal becomes emaciated. In many cases, 

 there are bedsores which render the animal liable to a gen- 

 eral septic infection. Death is due either to an infection of 

 this kind, to hypostatic congestion of the lungs, or to collapse. 



Diagnosis. A suspicion as to the existence of the disease 

 is raised if a dog occasionally, when changing its position or 

 sometimes without obvious cause, utters cries. The following 

 sjanptoms are characteristic of the disease : circumscribed but 

 asymmetrical hyperalgesia of the skin, muscular spasms of the 

 same and other parts of the body caused by passive move- 

 ment of parts of the spine, symptoms of pain, the exact seat 

 of which cannot be localized, in the later stages, loss of sensa- 

 tion in those parts which were previously hyperalgesic, paraly- 

 sis of the muscles originally in a condition of spasms, ill de- 

 fined areas that are in a condition of anesthesia, and, finally, 

 symptoms indicative of pressure upon the cord. 



The disease is most likely to be confounded with compres- 

 sion of the spinal cord, due to intervertebral enchondrosis, and 

 as pointed out by Dexler a differential diagnosis is not always 

 possil)le. The most important differential symptom is that in 

 the last named disease the symptoms are localized up to the 

 time of death, and indicate compression of the cord from the 

 outset. In the ossification of the membranes, there is a grad- 

 ual extension of the disease, and at first only individual nerves 

 are involved, but later symptoms of chronic meningitis make 

 their appearance. Compression of the cord is indicated wlien 

 the area of sensory and motor paralysis is sharply circum- 

 scribed from the start, and the gait is consequently very un- 

 steady; the paralysis in such cases is supranuclear. On the 

 other hand, primary ossifying degeneration of the dura is in- 

 dicated under the following circumstances : the reflexes which 

 at the outset are very active, become gradually weaker, the 

 muscular spasms which rapidly increase in severity are fol- 

 lowed by relaxation and atrophy of the muscles, the area that 

 is devoid of sensation is ill defined, and the disease is obviously 

 progressive in character. Taking these and other points into 

 consideration, it is quite possible to exclude spinal pressure. 



