

DOURINE OR MALADIE DU COIT 49 



The Symptomatology and Diagnosis of Dourine. 



Miscellaneous Notes. 



In previous reporrts on Canadian dourine, Dr. Eutherford has laid stress on the 

 preat difficulty of diagnosing this disease with any certainty during its earlier 

 stages and has drawn attention to the apparent mildness of the infection in many 

 eases, especially in mares. In these respects, my own observations are in complete 

 accordance with those of D11. Rutherford. 



A careful study of the cases detailed in this report will give much more infor- 

 mation than any attempt of mine at a general description of the symptoms and 

 ^'ourse of dourine (such may be found in the text-books and clinical literature upon 

 »he subject, but this literature I have found very misleading, not stating with suffi- 

 oionl clearness the fugitive chanacter, the frequency or otherwise of the symptoms). 



Many authors commence their discourses on the symptoms by saying that they 

 may be divided into three stages. Baldrey (Journal of Comparative Pathology, 

 March, 1905) states that these stages are distinct, and may, if the case is carefully 

 watched, be recognized with comparative ease. This has been the exception rather 

 than the rule in my experience with Canadian dourine. 



Lingard, in his ' Report on Dourine,' 1905, states that what really is observed 

 in practice is an overlapping, or a partly concurrent exhibition of certain symptoms 

 referable to the respective periods, and goes on to say that the arrangement is purely 

 an arbitrary one, simply utilized for the sake of description. 



It is well, I think, to remember this reservation. The following notes may help 

 to put the diagnostician on his guard. 



In the case of mare No. 36, a stabled animal, and, therefore, under daily obser- 

 vation, the first visible signs of disease werie symptoms originating from the central 

 nervous system, which belong, according to the arbitrary division, to the Hhird ' 

 stage. These indications were followed, by the * first ' stage ,namely, tumefaction of 

 the genitalia, sexual excitement, &c. The first appearance of symptoms belonging 

 to the * second ' stage, namely, patchy infiltrations of the skin, the so-called- plaques, 

 were concurrent with the nervous manifestations, and have laten appeared when only 

 a trace of the ' first ' and ' third ' stage remains. 



In the case of experimental animal No. 39, the disease ran an acute course, 

 terminating fatally 139 days after infection. Nervous symptoms predominated 

 throughout the infection. 



In the case of experimental animal No. 29, dourine parasites were present in. 

 the vaginal mucus at irregular intervals from the 85th to 229th day after infection, 

 and yet only at the end of this period have there appeared any visible signs of dis- 

 ease, these being more or less indefinite and limited to a slight tumefaction of the 

 vulva and a somewhat swollen, anaemic, vaginal mucous membrane. 



These may be extreme cases, but others can be cited, both in naturally and 

 experimentally infected equines. It is only necessary, I think, to emphasize the 

 fact that symptoms may appear shortly after, or not for a very long period following 

 infection, or that they may abate or disappear for equally long periods at any stage 

 of the disease, and lastly, that loss of co-ordinate locomotion or other signs of nerrvoua 

 derangement may be the first and only signs of the disease visible to the naked eye. 



Oedema. — Most authors argue that the only truly pathognomonic sign of disease 

 is the eruption of the cutaneous plaques. These patchy infiltrations of the skin, 

 however, have been found so rarely, in cases that have come under my observation, 

 that some other sign has had to be seanched for. 



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