Staying safe with dogs is easier when you can read their body language.  Check out these tips from Purina.

In the most fundamental way, dogs are great communicators. We understand that a beeline for the front door means he’s happy to see you. We know that a lethargic walk means he’s feeling under the weather. We know a pooch is craving a snack when we catch him staring at the treat jar. Our dogs read us with ease—the average pooch understands up to 165 words, signs, and signals.

https://www.purina.com/articles/dog/behavior/how-to-read-dog-body-language