Humans have learned to spit while we brush and have mastered this over the years. While most dog breeds are pretty smart, asking your dog to spit and rinse may be beyond their skillset. Human toothpaste contains harmful ingredients, such as fluoride, foaming agents, xylitol, and detergents that dogs should not ingest. Swallowing our minty fresh teeth products can cause gastrointestinal issues, including diarrhea, runny stools, and vomiting.