Is It Safe for Dogs To Drink Out of Shared Water Bowls?

Contamination
When multiple dogs drink from the same water bowl there is a
higher chance of contamination from saliva bacteria viruses or parasites that can be present in the soil or the mouths of infected dogs. This can lead to the spread of diseases such as canine influenza and various bacterial infections.
Dirt at dog parks or communal parks can be full of parasites that live in the soil such as hookworms roundworms and giardia Butzer says. She adds that the same goes for dog feces. Dogs with runny noses or a cough can also transmit the Bordetella virus through their saliva into communal water bowls spreading kennel cough to your pet she continues. Plus dog urine may contain leptospirosis in it if the dog is infected she continues.

Dogs with compromised immune systems or those prone to allergies and sensitivities may be more susceptible to contracting illnesses or experiencing adverse reactions from shared water sources.
Hygiene
Communal water bowls may not always be cleaned and sanitized frequently or adequately which can lead to the buildup of bacteria and other pathogens. Stagnant water can become a breeding ground for harmful microorganisms. And its possible for our dogs to pass these germs to people and other animals 1 Drinking from a dirty water bowl is especially a concern in dogs with illnesses or weakened immune systems.
Behavioral Concerns
Dogs who tend to be shy or fearful may become stressed or anxious when sharing a water bowl with other dogs. Additionally some dogs may exhibit territorial behavior