الفهرس 
ACKNOWLEDGMENTS
Sig ns of dehydration and hypovolemic shockOnly 14 pages are availabe for public view
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Abstract
A total number of (170) newly born calves of both sexes aging from 1-30 days old were examine in the present study, 70 calves were apparently clinically healthy while 100 calves were suffering from enteritis. The animals were used for determination of the aerobic bacterial causes of enteritis with special reference to Escherichia coli infection. Some of the calves were belonged to Misr El-Khair farm-Assiut Governorate, farm of Faculty of Agriculture, veterinary teaching hospital, Assiut university as well as small holders at Assiut and Sohag governorates.
Diarrheic calves were subdivided according to clinical examination such as dehydration, temperature, sunken eyes and suckling affinity and others into three groups:
1- Mild diarrhea (n=45)
2- Moderate diarrhea (n=40)
3- Severe diarrhea (n=15)
All animals were subjected to careful clinical and laboratory examinations.
Fecal samples were obtained directly from the rectum of each calf by using sterile plastic swabs and transported to laboratory in a cold champer container for bacteriological culture on the same day.
Two blood samples were collected from examined calves
a) Whole blood samples with anticoagulant were collected for total blood cells count (TWBCs G/l, TRBCs T/l, Hb g/dl, PCV %, MCV fl, MCH pg, MCHC mg/dl).
b) Blood samples were collected without anticoagulant for biochemical analysis of serum (Glucose mmol/l, Total protein g/dl, Sodium mmol/l, Chloride mmol/l, Pottasium mmol/l, Creatinine mg/dl and Blood urea nitrogen mmol/l).
The most important results
1. Bacteriological Findings
a) The percentage of pathogenic E. coli infection was 44% in diarrheic calves and 22% in apparent clinically healthy ones. E. coli strains were belonged to 13 different serogroups (O111:H2, O26:H11, O128:H2, O91:H21, O55:H7, O127:H6, O113:H4, O124, O121:H7, O8, O86, O44:H18 and O146:H21). By Polymerase Chain Reaction (PCR) examination to E. coli strains, the result revealed that STa (12.12%), Stx1 (15.15 %), Stx2 (12.12%), Stx1 and Stx2 (9.09%), STa and Stx1 (6.06%) and STa and Stx2 (6.06%).
b) No salmonella infection was reported either in diarrheic or apparent clinically healthy calves.
c) The prevalence of Enterobacter species was 10% in all examined calves (apparent clinically healthy calves and diarrheic calves).
d) The prevalence of Citrobacter freundi was 6% in diarrheic calves only.
e) The prevalence of Klebsiella pneumoniae was 4% in diarrheic calves only.
f) The prevalence of Serratia liquefaciens was 2% in diarrheic calves only.
g) The prevalence of Providencia rettgeri was 4% in all examined calves (apparent clinically healthy calves and diarrheic calves).
2. Hematological findings
a) There was significant (p≤0.05) increase in the level of total red blood cells(T/L) count in mild diarrhea if compared with apparent clinically healthy ones.
b) Highly significant (p≤0.01) increase in the levels of total red blood cells count (T/L) in moderate and severe diarrhea and highly significant increase in the level of total white blood cells count(G/L) in severe diarrhea if compared with apparent clinically healthy ones.
c) A significant (p≤0.05) increase in the level of Hb concentration (g/dl) in severe diarrhea as compared with apparent clinically healthy ones.
d) A significant (p≤0.05) increase in PCV% in severe diarrhea as compared with apparent clinically healthy ones.
e) Highly significant (p≤0.01) increase in MCHC (g/dl) in severe diarrhea as compared with apparent clinically healthy ones.
3. Serum biochemical findings
a) There was a significant (p≤0.05) decrease in the level of glucose (mmol/l) in severe diarrhea as compared with apparent clinically healthy ones.
b) A significant (p≤0.05) increase in the levels of total protein (g/dl) and creatinine (mg/dl) in severe diarrhea as compared with apparent clinically healthy ones.
c) Highly significant (p≤0.01) increase in the level of blood urea nitrogen (mmol/l) in severe diarrhea as compared with apparent clinically healthy ones.
d) There was highly significant (p≤0.01) decrease in the level of sodium (mmol/l) in severe diarrhea as compared with apparent clinically healthy ones.
e) A significant (p≤0.05) decrease in the level of chloride (mmol/l) in severe diarrhea as compared with apparent clinically healthy ones.
f) Highly significant (p≤0.01) increase in the level of potassium (mmol/l) in severe diarrhea as compared with apparent clinically healthy ones.
from the before mentioned, we could conclude that:
1. High percentage of enteritis in neonatal calves (58.8%) were reported suggests that special care for these animals during this critical age is highly recommended.
2. The study showed a high frequency of pathogenic E. coli (66%) including EHEC, ETEC, EPEC and EIEC in both healthy and diarrheic calves.
3. EHEC were the highest distributed E. coli strain either among diarrheic or healthy calves revealing its important participation in the etiopathogenesis of diarrhea in calves and reinforcing the role of these animals as a reservoir of potentially pathogenic E. coli for humans.
4. The present work provides updated information on the molecular characterization of pathogenic E. coli strains based on demonstration the presence of the EHEC and ETEC virulence genes: colonization factor (K99+) and enterotoxins (Stx1, Stx2 and STa) in both healthy and diarrheic calves.
5. The course and severity of E. coli infection were varied from mild, moderate and severe. Mental status, suckling affinity and degree of dehydration represent the cornerstone for clinical assessment of the severity of E. coli diarrheic. Semicomatozed calves in sternal or lateral recumbency, with no suckling affinity and severe degree of dehydration were suffered from severe E. coli diarrhea.
6. Hematological and biochemical pictures in diarrheic neonatal calves were of great value for laboratory assessment of the severity of E. coli diarrhea. The degree of hemoconcentartion, disturbance in potassium ion and renal function test considered as prognostic biomarkers in E. coli diarrhea. Significant increase in PCV and serum total protein (hemoconcentartion), potassium ion (hyperkalemia) as well as serum urea and creatinine (uremia) were evident in severe E. coli diarrhea in neonatal calves.The severity of clinical signs was correlated with the severity of change in the hematological and biochemical findings. Therefore, cliniocolaboratory assessment of E. coli diarrhea in neonatal calves could be achieved under field condition.