Dubey J P, Speer C A, Epling G P
Am J Vet Res. 1982 Dec;43(12):2147-64.
The development of Sarcocystis cruzi was compared in 3- to 14-day-old calves (n = 38) inoculated with 55,000 to 500,000,000 sporocysts from intestinal scrapings of coyotes, and euthanatized and necropsied on postinoculation days (PID) 4 to 153. From PID 15 to 19, the calves remained clinically normal, except for fever (greater than or equal to 40 C), during the development of 1st-generation meronts, and lesions in calves euthanatized at this time were confined mainly to mesenteric lymph nodes and consisted of focal necrosis due to vascular thrombosis. On PID 26, calves became sick, coincident with maturation and rupture of 2nd-generation meronts. In calves euthanatized from PID 26 to 28, the main lesion was hemorrhage in many organs and 1st- and 2nd-generation meronts were located subendothelially in unidentified cells between endothelium and tunica elastica. In calves euthanatized on PID 31, inflammation was pronounced in many tissues; this was also seen in calves euthanatized from PID 31 to 46 and corresponded to individual merozoites and the early development of sarcocysts. Inflammation began to subside by the time sarcocysts were recognizable (PID 67). Nonsuppurative hepatitis occurred in calves euthanatized from PID 15 to 153.
对3至14日龄犊牛（n = 38头）感染克氏肉孢子虫的发育情况进行了比较，这些犊牛接种了来自郊狼肠道刮片的55,000至5亿个孢子囊，并于接种后天数（PID）4至153进行安乐死和剖检。在PID 15至19期间，第一代裂殖体发育时，犊牛除发热（大于或等于40℃）外，临床症状正常，此时安乐死的犊牛病变主要局限于肠系膜淋巴结，由血管血栓形成导致的局灶性坏死组成。在PID 26时，犊牛发病，与第二代裂殖体成熟和破裂同时发生。在PID 26至28安乐死的犊牛中，主要病变是许多器官出血，第一代和第二代裂殖体位于内皮和弹性膜之间未识别细胞的内皮下。在PID 31安乐死的犊牛中，许多组织出现明显炎症；在PID 31至46安乐死的犊牛中也观察到这种情况，这与单个裂殖子和肉孢子虫的早期发育相对应。当肉孢子虫可识别时（PID 67），炎症开始消退。在PID 15至153安乐死的犊牛中发生了非化脓性肝炎。
