EEPOBT OF THE BUREAU OF ANIMAL INDUSTRY. 87 



appearance of hog cholera in the same herd. But sufficient evidence 

 had already been procured to show in a striking manner the non- 

 identity of the two diseases. In this outbreak we were for the first 

 time enabled to convince ourselves of the important fact that in the 

 severer forms croupous and diphtheritic lesions of the large intestine 

 are usually present. These may lead to superficial necrosis of the 

 mucous membrane and the formation of ulcers if the animals live 

 long enough. This fact makes the diagnosis between hog cholera 

 and swine plague far more difficult, unless bacteriological methods 

 are employed. It at the same time accounts for many discrepancies 

 in the results of former investigators in this field, who regarded all 

 infectious swine diseases due to one cause. In the following pages 

 the autopsy and bacteriological notes are given with a few brief 

 comments. Some of the earlier cases were not examined from a 

 bacteriological stand-point, as the disease was at first regarded as 

 hog cholera by the one in charge of the animals. The notes of the 

 hasty examination are given, however, being valuable as far as 

 they go: 



Pig No. 406, male, three months old, died February 1. Skin of the ventral aspect 

 of body and inner surface of limbs reddened. Superficial inguinal glands greatly 

 enlarged and diffusely reddened. Spleen very sligntly tumefied; on section dark- 

 colored and rather friable; on cortex small, elevated, blood-red points. Interlobular 

 tissue of liver increased in quantity ; gives a harsh, gritty sensation to the hand 

 when cut. Medulla of kidneys deeply congested. Lungs normal. Both ventricles 

 of heart contain small quantities of dark, imperfectly coagulated blood. Consider- 

 able serum in pericardial cavity. Lymphatic glands of meso-colon and meso-csecum 

 greatly tumefied and very dark red throughout. Those of mesentery but slightly 

 affected. Quite extensive, firm adhesions between caecum and adjacent coils of 

 colon. Large intestine filled with a semi-liquid mass containing much sand. Patch 

 of mucous crypts at base of ileo-csecal valve converted into an ulcer nearly 2 

 inches across. The intestinal wall forming the base of this ulcer nearly three- 

 fourths inch thick. The superficial necrotic portion, about one-fourth inch thick, 

 is separated from the deeper neoplastic portion of the wall by an irregular hernor- 

 rhagic line. This latter portion is streaked with blood. The serous membrane of 

 this patch is covered with radiating vessels of inflammatory origin, and adherent to 

 colon. Three other ulcers in caecum about three-fourths inch in diameter; in struc- 

 ture like the above. The mucous membrane of caecum and colon very deeply con- 

 gested, approaching hemorrhage. Lower portion of ileum contains a few petecchiae. 

 Stomach normal and filled with food. 



This was without doubt a case of genuine hog cholera. The deep ulcerations in 

 the caecum, taken together with healthy lungs, are sufficient evidence. No cultures 

 were made from the spleen of this animal, although this would have been very de- 

 sirable in the light of future events. The case is given to indicate the origin of the 

 hog cholera, which appeared later in the same herd, together with the lung disease. 

 The following attempt to infect another animal did not give any definite result: 



In order to determine more precisely the nature of the disease affecting 406, No. 

 358, from another lot, was fed with portions of the spleen and large intestine of this 

 animal. Unfortunately the animal was placed in a pen which had been long in- 

 fected with hog cholera, but in which the animals had lately failed to take the dis- 

 ease. The feeding took place February 1. It grew very feeble a week after; its 

 appetite began to fail; it finally remained lying down all day, and was found dead 

 February 20. 



Autopsy notes. February 21. Superficial inguinal glands enlarged, bluish-red ; 

 parenchyma dotted with bright red points. Some straw-colored serum and a few 

 strings of fibrin in abdominal cavity. Liver dark, filled with blood : right lung 

 hypostatic ; right heart filled with dark, partially-coagulated blood. Large intes- 

 tine distended with consistent fecal masses. Mucosa considerably reddened ; mi- 

 nute vessels injected. Two old, healing ulcers, three-eighths inch across, in caecum ; 

 stomach normal ; spleen cultures remain sterile. 



In the same pen with No, 406 were Nos. 403, 404, and 405. No. 403 died February 16. 



Autopsy. Pig three months old. Skin over throat, inner aspect of limbs, and 

 pubic region, reddened ; entire ventral aspect of body slightly so. Subcutaneous 

 fatty tissue tinged red. Superficial inguinals enlarged and deeply reddened through- 



