Venous blood pressure relative to the development of bovine udder edema.

Cranial superficial epigastric (milk vein) and jugular venous blood pressure were measured in 8 cows with udder edema and in 3 normal control cows at least 2 weeks before parturition, at parturition, and 2 weeks after parturition. Cows with udder edema had a significant mean increase (P less than or equal to 0.05) in cranial superficial epigastric venous pressure at parturition when compared with pressures 2 weeks prepartum and 2 weeks postpartum. Unaffected control cows had an insignificant increase in cranial superficial epigastric venous pressure during these 3 periods of measurement. There was an insignificant increase in jugular venous blood pressure during the 3 periods of measurement in affected and control cows. A correlation was observed between mammary blood flow and cranial superficial epigastric blood pressure at parturition (r = -0.659, P less than or equal to 0.05).