A liquid solution, gingival sealant containing polymers that form a barrier film upon application was evaluated in dogs. It is a non-toxic, low viscosity, hydrophilic barrier sealant that dries in approximately 10 to 15-seconds after subgingival application. It was designed as a preventative to be applied immediately following a professional oral hygiene procedure in order to block plaque and calculus formation in the sulcus and aid in the prevention of periodontal disease in companion animals. Additionally, the polymer was designed to promote an aerobic environment in the sulcus by oxygen and water transport through engineered pores within the polymer. A 30-day split-mouth, blinded study in two groups of 15 beagle dogs was used. Plaque was significantly (p < 0.05) reduced on the side receiving the sealant by 30.0% and 50.5% (average = 40.3%) in groups 1 and 2, respectively. Calculus was significantly (p < 0.05) reduced on the side receiving the sealant by 27.2% and 20.0% (average = 23.6%) in groups 1 and 2, respectively. Gingival inflammation was monitored to assess product safety. Sides receiving sealant showed no statistically significant differences in gingival index score. No adverse events were observed in the study. This study demonstrates that this gingival sealant can be used as another valuable tool for aiding in the prevention of periodontal disease in dogs.