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V. 



THE PEESENCE OF SPIEOCH^TES IN CEETAIN INFECTIVE 

 SAECOMATA OF DOGS. 



By a. E. METTAM, B Sc, M.E.C.V.S., M.E.I.A., 

 Principal of the Eoyal Veterinary College of Ireland. 



Plate VL, Figs. 5, 6. 



Read April 13. Ordered for Publication May 25. Published August 21, 1908. 



There occurs in and upon the genital organs of dogs a new growth, the 

 structure of which has been variously interpreted by observers. According 

 to some it is a carcinoma ; others describe it as a sarcoma or lympho- 

 sarcoma; and, yet again, others maintain it to be nothing more than a 

 granuloma, the response to some agent that has not been hitherto seen or 

 described. If it is to be included in the latter class, then it may be compared 

 to the lesions observed in actinomycosis, in tuberculosis, or in glanders, the 

 cause of which is known ; but the structure of the new growth differs con- 

 siderably from the lesions observed in all three of these infections. The 

 disease is capable of being inoculated from diseased to healthy animals by 

 grafting, and infection occurs naturally at coition. The tumour rarely 

 reproduces by metastasis, though cases are recorded of such, and not 

 infrequently after surgical interference the tumour may not recur, or, if 

 only partially removed, the part remaining may degenerate and ultimately 

 disappear. On the other hand, it may attain a large size, and if not 

 removed may necessitate the destruction of the animal, as the condition 

 becomes repulsive. As Wade has recently shown, the patient not infrequently, 

 indeed we may say generally, has an interstitial nephritis, which lesion may 

 develop as the result of a toxin elaborated by the agent, causing the new 

 growth. At any rate, the interstitial nephritis being so commonly an associated 

 lesion, its appearance must be considered as something more than a mere 

 coincidence. In considering this infective tumour of the dog, it is impossible 

 to ignore the human syphilis and the disease in the horse known as dourine. 

 In the lesions of syphilis Schaudinn and Hoffman, three years ago, showed 

 that certain minute parasites — spirochaetes — were to be demonstrated ; and 



