CHAPTER XV 



ON THE INFECTIVE GENITAL TUMOURS OF DOGS 



THE above name has been given to a kind of tumour that is not 

 uncommon in the genital organs of dogs. The lesions from their 

 histological structure have been variously pronounced to be epithelial 

 cancer, 1 granulation tissue, 2 round-celled sarcoma, 3 lymphosarcoma, 4 

 blastomycetic tumour, 5 and round-celled sarcoma with ' true meta- 

 stases' 6 in the testes. These conflicting opinions reflect the 

 perplexing state of thought that prevails at the present time with 

 regard to malignant tumours in general, and on this account this 

 disease merits the closest examination. First, one should consider 

 the more striking points in the natural history of the disease. As 

 far as is known, new cases arise only by sexual contact of a healthy 

 with a previously infected animal. The disease is rare in old dogs, 

 and has not been observed as a natural occurrence in other than 

 sexually mature individuals. It is easily transmitted experimentally. 

 The effects of inoculating fragments of the growths into the sub- 

 cutaneous tissue of other dogs was thus described by the late Dr. 

 Washbourn and Dr. Bellingham Smith : T 



1 Geissler, Verhand. der Deutsch. Gesellsch.fiir Chirurg., 1895. 



2 Duplayand Cazin, Transactions of the International Congress at Rome, 1894; 

 and Bashford and others, Imperial Cancer Research Fund, 1905. 



3 Washbourn and B. Smith, Transactions of the Pathological Society, London, 



1897- 



4 Sticker, Zeit.fiir Krebsforschung., 1904. 



5 Sanfelice, Riforma Medica, 1904. 



6 Shattock and Seligman, Reports of the Pathological Society, Brit. Med. 

 Journ., 1907. 



7 Washbourn and Bellingham Smith, Brit. Med. Journ., December 17, 1898. 



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