2010 Volume 63 Issue 11 Pages 861-865
Wax-teat bougie (A), silicone cannula (B) and cutgut-teat dilator (C) were placed into the teat canal (TC) for three days or nine days in eight non-lactating Holstein cows. In four other lactating cows, A and B inserts were placed for seven days. The teats were examined by theloscopy at intervals of three days in the non-lactating cows. At necropsy, the teat samples were collected from both the non-lactating and lactating cows for histopathology. Theloscopically, luminal dilation, desquamation of the horney layer, hemorrhage of the teat canal, submucosal hemorrhage and roughing of the Fürstenberg's rosette (FR) were observed in the teats administered with B and C inserts. The histopathological features in those lesions included mucoepithelial necrosis, leukocytic infiltration and fibrosis in the TC and FR. However, most teats administered with the A insert showed only a mild infiltration of lymphocytes in the TC and FR, suggesting that the A insert has less inflammatory information than the B and C inserts. The results of the present study suggest that the A insert is less irritative for the normal bovine teat canal.
