Attaching and effacing Escherichia coli infection as a cause of diarrhea in young calves

A form of enteric Escherichia coli infection was identified in 60 calves from 59 farming operations. The E coli responsible for these infections principally colonized the colon, inducing a distinctive lesion described as attaching and effacing. Hemorrhagic enterocolitis or blood in the feces was observed on 40% of the farms. Of affected calves, 86.6% were dairy calves (average age, 11.8 days). Forty-four calves were infected concurrently with other enteropathogens (cryptosporidia, rotavirus, coronavirus, enterotoxigenic E coli, bovine viral diarrhea virus, coccidia). Verotoxin-producing E coli was recovered from 31 calves; 8 were serotype O111:NM isolates, 3 were serotype O5:NM, and 1 was serotype O26:NM.     

Studies on diarrhea of young calves. 1. Quantitative analysis of the gastrointestinal flora in clinically healthy calves and in calves with diarrhea]

Quantitative composition of gastro-intestinal-flora was determined in 23 clinically healthy calves and the course of germ spreading was followed up. In comparison with these healthy animals in 25 diarrhoea affected calves at the age of 4 to 17 days there could be observed signigicant differences only in few parts of the gastro-intestinal-tract concerning the quantitative composition of germ flora. Only in 3 animals enterotoxin producing E coli strains could be detected.     

Haemophilus somnus as a cause of bronchopneumonia in calves

A bacteriological examination of the pulmonary tissues of calves suffering from bronchopneumonia was complemented by a microaerophilic or anaerobic cultivation. Thirty-two strains (23.7%) of a microorganism hitherto not described in Czechoslovakia were isolated during the examination of 135 calves with disorders of the respiratory system. On the basis of the growth, morphological, biochemical and serological properties, the microorganism was identified as Haemophilus somnus. Chocolate agar supplemented with yeast extract, and blood agar were used for the cultivation. Incubation took place in a microaerophilic medium with 10% carbon dioxide or in an anaerobic medium. Serums against the collection strain of Haemophilus somnus were prepared in rabbits for the serological diagnosis. These antiserums reacted with all tested strains during test tube agglutination but did not enter cross reactions with other bacterial species. The coagglutination test, which was verified, did not provide reliable results.     

Rotavirus as a cause of diarrhea in pigs.

A rotavirus (reovirus-like agent) was associated with diarrheal diseases occurring in 1- to 4-week-old suckling pigs in 8 herds and in weaned pigs in 2 herds. Transmissible gastroenteritis virus was also detected in 2 of these herds, as was enteropathogenic Escherichia coli in 5 herds. Morbidity was generally greater than 80% in pigs of the affected age group within these herds, and mortality from diarrhea ranged from 7 to 20%. The disease due to rotavirus in suckling pigs appeared similar to the syndrome commonly referred to as milk scours, white scours, or 3-week scours. Diarrhea and villous atrophy, resembling that seen in transmissible gastroenteritis, occurred in naturally infected pigs and in gnotobiotic pigs experimentally infected with rotavirus. Diagnosis was accomplished by immune electron microscopy of intestinal contents and by immunofluorescent staining of enterocytes. A massive infection of enterocytes with rotavirus was demonstrated by immunofluorescence, which helps explain the pathogenesis of this disease. The apparent rarity of clinical rotaviral infections in suckling pigs greater than 7 days old is probably due to the acquisition of passive immunity from immune sows.     

Campylobacter jejuni and Campylobacter coli inoculation of neonatal calves

Three groups of neonatal calves were inoculated orally with pathogenic strains of Campylobacter jejuni or C coli. The calves developed a mild, self-limiting enteritis characterized by thick mucoid feces. Bacteremia and fecal shedding of Campylobacter were sporadic in all inoculated calves. Two groups of calves were killed 1 to 3 weeks after inoculation to study the pathogenesis of infection. Postmortem culture of tissues revealed C jejuni or C coli most frequently in the ileum, cecum, colon, and blood. Clinical or pathologic differences between C jejuni-inoculated and C coli-inoculated calves were minimal.     

Cryptosporidium infection as a cause of calf diarrhea

Cryptosporidiosis is a self-limiting protozoal disease of the intestinal tract. Although identified as possible agents of calf diarrhea less than 15 years ago, Cryptosporidium spp. are now believed to be common in calves and in many other host animal species worldwide. Recent literature on all aspects of cryptosporidiosis in calves is reviewed, predicaments in diagnosis and management are discussed, and public health concerns are raised.     

Histological studies of the occurrence of organisms shaped like Campylobacter in the abomasum of calves]

The mucosa of the abomasum is a strongly acidic and therefore germ poor, but not entirely germfree environment. Only in isolated areas of the fundic glands zone were straight rods in the foveolas, and even more seldom spiral shaped bacteria could be encountered. They had no relation to the inflammatory infiltrates. On the other hand, Campylobacter-like organisms were more often observed in the pyloric region and, preferably, in a narrow zone following the cutaneous mucosa of the omasum. These organisms appeared to have a different size (1.3 to 2.4 microns length and 0.4 to 0.8 microns width) and they occurred deep inside the glands in an almost pure fashion. Whereas they caused no visible reaction of the tissue in the narrow cardiac zone, their occurrence in the pyloric region was several times connected with neutrophilic-rich infiltration. It ought to be tested, whether Helicobacter are among these Campylobacter-like organisms, which cause a disease leading up to ulcerations in calves similar to gastritis B in humans.     

哺乳犊牛腹泻的防治

犊牛腹泻是哺乳期犊牛常见多发病之一，死亡率较高，多发生于出生后前三周，一般为胃肠消化功能紊乱。特征是消化不良和拉稀，顽固性腹泻可使犊牛衰竭而亡。腹泻分为营养性腹泻或饲养管理不当而使犊牛更易患病原性腹泻，其病原主要是大肠杆菌。     

Study on diarrhea in young calves. 2. Pathomorphological studies in clinically healthy calves and in calves with diarrhea

Pathological-anatomical and histological investigations were performed in 49 calves aged from 1 to 18 days, 26 of them being affected by diarrhoea, 23 being without clinical signs. In both the groups above all rhinitis, gastritis and typhlocolitis could be observed, thus the affection could be characterized as rhinogastrocolitis. Significant differences only existed between diarrhoea affected and clinical incospicuous calves concerning the macroscopic signs of the colon, periportal infiltrates of the liver and thymus in involution. The peak of inflammatory reaction is in general reached at the 7. to 10. day of life. In concordance with bacteriological findings the results refer to an affection not due to coli infection. Virus etiology may not be excluded and has to be examined in further studies.     

Protozoan infection causes diarrhea in calves

The role of protozoan parasites in the etiology of diarrhea in calves is highlighted with emphasis on correct diagnosis. In neonatal calves, Cryptosporidium parvum is isolated in more than 44% of the faeces of diarrhetic calves. In calves older than one month, both Eimeria bovis and E. zuernii, and Giardia duodenalis are associated with diarrhea and poor growth. Clinical diagnosis has to be confirmed by examination of host faecal material. Both for C. parvum and G. duodenalis immunological assays are available. Control measures must aim to reduce or prevent oocyst or cyst transmission, by combining management measures, desinfection and chemotherapeutic treatment.