Treatment of diarrhea of neonatal calves.

Therapeutic strategies for the treatment of diarrhea of neonatal calves should be logical and should be targeted at correction of physiologic dysfunction. Appropriate, specific antimicrobial or antiprotozoal therapy should be instituted when colibacillosis, salmonellosis, or giardiasis is confirmed or suspected. All calves with diarrhea should be rehydrated if necessary, and proper nutritional support should be provided. Antisecretory agents such as flunixin meglumine and bismuth subsalicylate may be beneficial for treatment of calves with colibacillosis and salmonellosis. Adsorbants, such as attapulgite and bismuth subsalicylate, also may reduce loss of fluids. Perhaps loperamide or a similar drug will be proven effective in calves in the future. Potentially harmful drugs include several antimicrobial agents when they are administered orally, because they result in malabsorption; kaolin and pectin, which increase loss of ions during diarrhea; and motility modifiers that cause a decrease in all types of intestinal motor function. Finally, success should be measured by indicators of production such as survivability, days treated, weight gained, and net profit. Our goal should be to restore and maintain the health of the calf, not simply to alter the volume and consistency of the feces.     

Treatment of hypernatremia in neonatal calves with diarrhea

Five hypernatremic, diarrheic, neonatal calves were treated mainly by the intravenous administration of 5% dextrose alone or with isotonic sodium bicarbonate. All calves recovered without complications. The average reduction rate of serum sodium concentration was about 4 times that recommended and has not been tried successfully before in hypernatremic scouring calves.     

Experimental model of type II bovine viral diarrhea virus-induced thrombocytopenia in neonatal calves.

Thrombocytopenia has been associated with type II bovine viral diarrhea virus (BVDV) infection in immunocompetent cattle, but the mechanism is unknown. The purpose of the present study was to develop and characterize a model of type II BVDV-induced thrombocytopenia. Colostrum-deprived Holstein calves were obtained immediately after birth, given a BVDV-negative and BVDV antibody-negative plasma transfusion, housed in an isolation facility, and randomly assigned to either control (n = 4) or infected (n = 5) groups. Infected calves were inoculated by intranasal instillation on day 3 of age with 10(7) TCID50 of the prototype type II isolate, BVDV 890, whereas control calves were sham inoculated. Blood counts and virus isolations from serum, white blood cells, and platelets were performed daily until day 12 after infection, at which time all experimental calves were euthanatized, and pathologic, virologic, and immunohistochemical examinations were performed. On physical examination, the control calves remained normal, but the infected calves developed pyrexia and diarrhea characteristic of type II BVDV infection. The platelet count decreased in all infected calves, and a statistically significant difference in the platelet count between control and infected calves was observed on days 7-12 after infection. In addition, the mean platelet volume and white blood cell counts also decreased. Examination of the bone marrow from the infected calves revealed immunohistochemical staining for BVDV antigen in megakaryocytes and evidence of concurrent megakaryocyte necrosis and hyperplasia.     

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.     

Age-related changes in carbohydrate tolerance in healthy neonatal calves

Calves at 3 to 4 days of age had higher plasma glucose concentrations during glucose and lactose tolerance tests (orally administered glucose and lactose) than when the calves were 8 to 9 days old. These observations may be accounted for by decreased insulin secretion and/or insulin sensitivity of the target tissues. Lower hepatic glucokinase activity in neonates also may allow increased passage of splanchnic glucose to the system circulation.     

Acute undifferentiated neonatal diarrhea in beef calves. I. Occurence and distribution of infectious agents.

Beef calves in a 48-cow herd were studied during one calving season from birth to ten days of age to determine the presence or absence of potentially enteropathogenic bacteria, viruses, and/or chlamydia in both normal and diarrheic calves. Calves were born and raised outside in large pens unless the ambient temperature was below minus 10 degrees F when calving was done inside. Fecal swabs, fecal aliquots, and nasal swabs were taken from each calf at 32, 128 plus or minus 3, and 248 plus or minus 3 hours of age and as soon after the onset of diarrhea as possible. Diarrhea was defined as that condition in which the feces contained less than 10% dry matter. Enteropathogenic Escherichia coli in feces were identified using the ligated gut loop procedure in calves and by feeding broth cultures to colostrum fed lambs seven to 16 hours old. Potentially enteropathogenic viruses were detected using a variety of methods which included tissue culture, fluorescent antibody, hemadsorption, and electron microscope techniques. Of the 40 calves studied, 32 (80%) developed diarrhea before ten days of age. Twenty-two strains of Escherichia coli which caused dilation of calf ligated intestinal loops were isolated from 11 scouring calves and from one normal calf. Nine out of ten strains of Escherichia coli which dilated ligated loops also caused diarrhea when fed to colostrum-fed lambs seven to 16 hours old. Using antibody technique a Reo-like virus was detected in the feces of 15 calves before, during, and after the onset of diarrhea. Four calves excreted both loop dilating strains of E. coli and Reo-like virus in the feces before ten days of age; in all cases the loop dilating E. coli were isolated from the feces prior to the demonstration of Reo-like virus. A Corona-like virus was also demonstrated in three of the 15 calves infected with Reo-like virus and a noncytopathogenic strain of bovine virus diarrhea virus was isolated from two of the 15 calves infected with Reo-like virus. A loop dilating strain of Citrobacter was isolated from one diarrheic calf. There was no consistent pattern of onset or duration of diarrhea in calves which excreted different infectious agents. Salmonella species, infectious bovine rhinotracheitis virus, parvovirus, adenoviruses, parainfluenza-3 virus, and Chlamydia species could not be demonstrated in any of the calves or their dams. No potentially enteropathogenic agents could be demonstrated in 11 of the 32 calves which scoured. These findings emphasize the complexity of the infectious aspect of the neonatal diarrhea syndrome and illustrate the difficulty in making an etiological diagnosis in field outbreaks of the calf scours complex.     

Relationship between diarrhea and peripheral leukocyte population in neonatal Japanese black calves

Neonatal Japanese Black (JB) calves show a high incidence of diarrhea. The objective of this study was to analyze the immune cell populations of neonatal JB calves in detail and examine its correlation with the incidence of diarrhea immediately after birth. Understanding the immune cell populations is helpful in clinics in order to determine the condition of the immune system for prevention of diseases. Blood samples were obtained from JB calves on the day of birth. The peripheral leukocyte populations were analyzed separately for calves that had diarrhea within 2 weeks after birth (diarrhea group; n = 26) and for calves without diarrhea (control group; n = 74). The numbers of the peripheral blood CD3(+)TcR1-N12(+) and CD8(+) T cells were significantly lower in the diarrhea group compared with the control group. These findings suggest that the congenital lower peripheral γδ and CD8(+) T cells results in a high risk of diarrhea in neonatal JB calves.     

犊牛腹泻的综合治疗

2009年4月份,锦州市某养牛专业户饲养的犊牛发生腹泻,该户共存栏15头犊牛有6头发病,发病率35%.经治疗,除1头死亡外,其他全部治愈.现将治疗情况作以介绍.