BACILLUS HEMOGLOBINOPHILUS CANIS 

 (FRIEDBERGER) 



(HEMOPHILUS CANIS EMEND.) 



T. M. RIVERS 

 From the Department of Pathology and Bacteriology Johns Hopkins University 



Received for publication February 18, 1922 



Friedberger in (1903), working in Pfeifler's clinic reported 

 finding in the preputial secretions of a dog a small, Gram- 

 negative, non-motile, hemoglobinophilic bacillus which he called 

 B. hemoglobinophilus canis. From his description it is difficult 

 to see how he differentiated it from H. influenzae except that 

 he isolated it from a dog instead of a human being. Odaira 

 (1912), also working with Pfeiffer, coinparcd H. pertussis, H. 

 influenzae and H. canis, and found that by agglutination tests 

 they were different. When complement fixation tests were used 

 less specificity was shown. 



Since the last pandemic of influenza much interest has been 

 taken in the so-called hemophilic bacilli in regard to their rela- 

 tion to disease, their growth requirements and their biological 

 reactions. It seemed, as advance had been made in differentiat- 

 ing many of these organisms by biological reactions, that H. 

 canis might also be differentiated culturally from closely allied 

 organisms. During the past year six strains have been isolated 

 from the preputial secretions of dogs. JMost of the male dogs 

 examined had a certain amount of pus in the preputial secre- 

 tions. Direct smears of this pus often showed numerous small 

 Gram-negative bacilli and when cultured H. canis was usually 

 found to be the predominating organism. Up to the present 

 this organism has been isolated from dogs only, but it is con- 

 cei^^able that laboratory workers and people who handle dogs 

 might show this bacillus accidentally in throat or nose cultures. 



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