A Big Yes! Slime and Biofilm are awful for dogs. Not just bad, they are fatal too. If your dog ingests slime or biofilm by mistake, it can risk his life. It contains so many harmful bacteria and germs. Those bacteria can lead to formation of dental plague which can even call forth periodontal disease, systemaic disease, or dental caries. However, if you clean, sterilize, and disinfect your dog's dishes and bowl regularly, you can easily make sure that your dog's health is not compromised.