This study aimed to evaluate the clinical, biochemical and hepatic ultrasonographic changes in ketotic dairy cows. For
that purpose, we examined 42 lactating Holstein- Friesian cows with ages from 3- 10 years old during the post parturient
period (up to 6 weeks postpartum). The cows were classified into control healthy (C=20), subclinical ketotic cows
(SCK=17) and clinical ketotic cows (CK=5). Clinically, anorexia and reduction in milk yield were observed in CK cows.
The ruminal movements showed a significant depression (P<0.05) in CK than SCK and control. The serum glucose,
insulin and cortisol showed a highly significant decrease (P<0.001) in CK and SCK than control. The serum NEFA and
BHBA showed a highly significant increase (P<0.001) in CK and SCK than control. Serum cholesterol and HDL levels
showed a significant (P<0.01) decrease in SCK and CK cows than control. Serum triglycerides (TG) and very low density
lipoprotein (VLDL) were significantly decreased (P<0.01) in CK than control. The serum activity of AST, ALT and GGT
were significantly increased (P<0.05) in CK cows than control. Serum Ca and P levels were significantly decreased
(P<0.05) in CK cows than SCK and control. Regarding the oxidative stress biomarkers, serum level of malondialdehyde
(MDA) showed a highly significant (P<0.001) increase in CK cows than SCK and control whereas, serum superoxide
dismutase (SOD) level was significantly decreased (P<0.05) in CK cows than control. Hepatic ultrasonography of ketotic
cows revealed varying degrees of fatty infiltration (focal and diffuse fatty infiltration) appeared as increased hepatic
echogenicity with a blurring of hepatic blood vessels. It is concluded that ketosis induced clinical, biochemical and
ultrasonographical changes in lactating cows. Oxidant injury could be implicated in the pathogenesis of the disease