K. F. MEYER 621 



cillus. In a shipment of fifty animals Feyerabend found twelve with tuber- 

 culosis. From the epidemiological investigations it must be concluded that the 

 disease was contracted from a tuberculous goat. The tubercle bacillus responsible 

 was in all probability a bovine type. Perla/ in a series of very fascinating observa- 

 tions and experiments, has shown that normal guinea pigs exposed to tuberculous 

 cagemates readily contract the same disease. In fact, it was noted that spontaneous 

 tuberculosis acquired from infected cagemates has with few exceptions the character 

 of an infection which has entered by way of the digestive tract, while guinea pigs 

 exposed to tuberculous animals in the same room but not in the same cage may 

 acquire tuberculosis which has the character of a bronchiogenic infection. The sources 

 of the disease are probably the tubercle bacilli which are discharged in the feces and 

 in the urine when the malady has reached its terminal stage. 



PROTOZOAN INFECTIONS 



The pathogenic role of a number of intestinal protozoan parasites to certain dis- 

 eases of the guinea pig is not entirely clear. There is no doubt that occasionally 

 emaciated, slightly anemic cadavers may be dissected and thoroughly studied bac- 

 teriologically without finding that a microbial cause can be detected. In these cases 

 the writer has always found the inflamed intestinal tube engorged either with Coc- 

 cidia or Trichomonas or Balantidium. Mostly young animals are the victims, and 

 it seems probable that the protozoa have some relationship to the enteritis and to the 

 emaciation. Strada and Traina^ and later Bugge and Heinke^ found 73 per cent of 

 their stock animals infected with Coccidia, and they ascribed this prevalence ac- 

 companied by sickness and the occasional death to a reduced resistance induced by 

 an inadequate diet. The views are unanimous that in adult animals the infection is 

 without any consequences. Sheather^ has described the parasite and given it the 

 name Eimeria caviae. He found that the various stages resembled those of the 

 Coccidia of the rabbit, but occurred only in the large intestines, particularly the 

 proximal portion of the large intestines, and not, as Strada and Traina stated, in the 

 liver. In his feeding experiments one fatal infection resulted on the fourteenth day 

 after the administration of the oocysts. 



Trichomonas infections are very common, and Perroncito, Galli-Valerio,^ as- 

 sumed that they were the inciting cause of a great mortality among the guinea pigs 

 of the Hygiene Institute at Lausanne. However, there is ample evidence that per- 

 fectly healthy animals may show ulcerations of the large intestine and cecum with 

 definite invasion of the tissues by the flagellates. Whether these lesions are primarily 

 caused by the Trichomonas has yet to be determined. Entamoeba cobayae and Ba- 

 lantidium caviae frequently found in the inflamed digestive tract are considered harm- 

 less commensals. Klossiella cobayae in the kidney tubules has been described by 

 Pearce.* 



'Perla, D.: J. Exper. Med., 45, 209 and 1025. 1927. 



= Strada, F., and Traina, R.: loc. cit. 



3 Bugge, and Heinke: Deutsche tierdrztl. Wclinschr., 29, 41. 1921. 



■* Sheather, A. L. : /. Compt. Path. 6^ Therap., 36-37, 243. 1923-24. 



5 Galli-Valerio, B.: Centralbl. f. Bakteriol., Orig. I, 27, 305. 1900. 



^Pearce, L.: J. Exper. Med., 23, 431. 1916. 



