Bismuth subgallate as a topical haemostatic agent at the palatal wounds: a histologic study in dogs

This study evaluated the early recovery process of the palatal wounds of dogs using bismuth subgallate. Five healthy adult male dogs underwent eight 5-mm partial-thickness punch biopsies in two paired columns on the palatal mastigatory mucosa. For the haemostasis, one side received moistened gauze pressure (test group 1), and the other received bismuth subgallate (test group 2). A description of the epithelium and connective tissue repair was made at 3, 7, 14 and 21 days. During the first days, a mass of disorganized tissue covered the connective tissue, in which there was intense chronic inflammation, and migration of epithelium cells from the edges towards the central region to close to the wound was seen. The final evaluation demonstrated well organized epithelial and connective tissues in all the samples. Epithelium thickness was measured at 0, 14 and 21 days, from images of the digitalized histological sections. In comparisons between the test groups, the bismuth subgallate group was slightly better than the saline group, but no statistically significant difference was found at 21 days. It was possible to conclude that bismuth subgallate did not interfere in the tissue repair of the palatal mastigatory mucosa in dogs.