Dourine. 577 



this disease. Many Arabian horses naturally acquire such white 

 spots on the dark skin, and in pure Arabs and grades this appear- 

 ance need not be held as evidence of dourine. 



Infected mares rarely conceive, and any that do so are likely to 

 abort before the sixth month. 



The systemic symptoms, nervous, paralytic, tremulous, dyspep- 

 tic, atrophic, cerebral and cachectic follow a similar course as in 

 the stallion. 



In grave and progressive cases the lesions of the generative or- 

 gans become very marked. The lips of the vulva become rigid 

 and distorted so that it remain's constantly open and the erect 

 clitoris con tinuall J' exposed. The skin of the vulva is tense, dry 

 and shining. lyameness is shown in one or both hind limbs, 

 knuckling over at the fetlock, shortening of the step, planting the 

 toe first and the heel later with a jerk, lack of balance, paresis 

 and even inability to rise. 



A disposition to trembling is common to both sexes, as is also 

 an intolerable itching of the skin which may make the animals 

 tear the lower parts of the limbs with the teeth. In either there 

 may be a local paralysis of a lip, an ear, an eyelid, or some other 

 part of the body. In both sexes the disease tends to extreme 

 anaemia, debility and emaciation, and to infective internal inflam- 

 mations (lungs, bronchia) or septic or purulent infections. 



Diagnosis. From urticaria this disease is to be distinguished 

 by the absence of lesions of the generative organs in the former, 

 by its association with change of food and digestive disorder and 

 by the absence of all evidence of contagion. 



From glanders it is to be distinguished in the same way by its 

 casual transmission by sexual connection only, by its restriction 

 to breeding animals, and by the irresponsiveness of the victim to 

 the mallein test. The progressive paresis and hebetude are 

 valuable diagnostic phenomena. From surra, by its avoidance 

 of non-breeding animals, its transmission by coitus, the immun- 

 ity of cattle, and the absence of marked regular febrile reactions. 



From chro7iic paraplegia it is distinguished by the same pre- 

 valence in breeding solipeds only, and by its mode of transmission. 



The greatest difficulty is experienced with the slight and com- 

 paratively bccult cases, and in some of these the history of the 

 infection of a number of breeding animals, which have been 

 37 



