My dog drank toilet water. Is he at risk for E. coli or giardia?

Hello. If your toilet was relatively clean, there is nothing to worry about as the water that goes to the toilet is the same that comes from the main line into the house for drinking. If your toilet is less than pristine, then thee is a small possibility of a bacterial infection. Forget about giardia, this is a parasite that is found in streams & bodies of water contaminated by wildlife feces. In the small chance that there was enough bacteria in the toilet water to cause an illness, you should watch for vomiting, diarrhea, nausea, loss of appetite, bloating or signs of abdominal pain. Most signs should show in the next 48-72 hours, so if Bentley makes it through the weekend with no problems, he will be perfectly fine. Thanks for using Petco Pet Education Center, formerly Petcoach.