632 COMMUNICABLE DISEASES OF LABORATORY ANIMALS 



common localization of one of the parasites (Dermatocoptes) is the external ear in 

 which a severe inflammatory process sometimes leads to an otitis media and then to 

 a purulent meningitis. The disease is readily transmitted by contact but can, ac- 

 cording to Gmeiner,' be easily cured by removal into coal oil of the scaly crusts which 

 are teeming with the insects and by repeated painting of the denuded skin, fissures, 

 and folds of the external ear with oil of caraway (one part) in almond oil (ten parts), 

 or tincture of larkspur seed (one part) and 90 per cent ethyl alcohol (three parts). 



From the published records one must conclude that the rabbit is heir to many 

 other spontaneous diseases, but since it is not unlikely that some of them are only 

 variations of the maladies already described, a detailed account is omitted. 



DISEASES OF MICE 



White mice are used extensively as experimental animals. Despite this fact, very 

 little is known regarding the normal physiology and pathology of this rodent. Only 

 quite recently Knorr^ has pointed out that this animal may be the source of many 

 errors (irregular temperature reaction, delay or inhibition of tetanic symptoms, 

 etc., due to starvation). Equally incomplete has been the knowledge regarding its 

 communicable diseases. However, the fascinating studies in the field of experimental 

 epidemiology conducted by Flexner,^ Amoss,"" Webster, ^ Pritchett,'' Topley and his 

 associates,' Neufeld and his co-workers,** and others have furnished complete infor- 

 mation regarding the common disease "mouse typhoid" and the less frequent Pas- 

 teurella infection. 



Loeffler' in 1890 studied the inciting micro-organism of a highly fatal (69 per 

 cent) epidemic among the stock mice of the Institute at Greifswald. He found a 

 motile, gram negative rod for which he proposed the name Bacillus typhi murium. 

 Since the virulence of the bacterium was also very high for field mice, he recommended 

 its use for the extermination of these destructive rodents. Smith'" was first to recog- 

 nize the relationship of the bacillus described by Loeffler with the hog-cholera bacillus 

 and the B. enter itidis of Gartner. Subsequently paratyphoid bacilli have been fre- 

 quently found in the organs of apparently "healthy" mice (Rothe, Kutscher," 



• Gmeiner: Deutsche tieriirztl. Wchnschr., 11, 69. 1903; also Jowett, W.: /. Comp. Path. &" 

 Therap., 24, 134. 191 1. 



^ Knorr, M.: Ccntralbl. f. Bakleriol., 99, 576. 1926. 



3 Flexner, S.: /. Exper. Med., 36, 9. 1922. ■* Amoss, H. L.: ibid., pp. 25, 45, 107. 1922. 



5 Webster, L. T.: ibid., pp. 71, 97. 1922; 37, 21, 2,Z, 231, 269, and 781. 1923; 38, 33, 45. 1923; 

 39, 129, 879, 265. 1924; 40, 397. 1924; 42, r. 1925. 



^Pritchett, I. W.: ibid., 41, 195. 1925. 



7 Topley, W. W. C: /. Hyg., 19, 350. 1921; 20, 103. 1921; 21, 10, 20, 226. 1922-23; Topley, 

 W. W. C, and Wilson, (l. S.: ibid., 21, 237, 243. 1923; Topley, W. W. C, and Ayrton, J.: ibid., 

 22, 222, 234, 305. 1924; 23, 198. 1924; Topley, W. W. C, and Wilson, J.: ibid., 24, 295. 1925; 

 Greenwood, M., and Topley, W. W. C: ibid., 24, 45. 1925; 25, 336. 1926; Topley, W. W. C: 

 Lancet, i, 477, 531, and 645. London, 1926; J . State Med., 35, 2, 63. 1927. 



* Neufeld, F.: Ztschr.f. Hyg. u. Infektionskrankli., loi, 466. 1924; 103, 471. 1924. 

 »Loef9er, F.: Cenlralbl. f. Bakteriol., Ori^'., I, 11, 129. 1S92. 



'"Smith, T.: ibid., 16, 231. 1S94. 



" See Uhlenhuth, P., and Hiibener, E.: Ilaiidb. d. path. Mikroorg. (2d ed.), 3, 1073. 1913. 



