What are common signs of aggression in dogs?

Common signs of aggression in dogs include behaviors such as growling and a stiff body posture. When a dog growls, it typically serves as a warning signal that the dog feels threatened or is ready to defend itself. Coupled with a stiff body posture, which may indicate that the dog is tense or alert, these signs suggest that the dog may not be feeling safe or secure and could potentially act aggressively if it perceives a further threat.

The other options describe behaviors that are generally linked to positive states or lower stress levels in dogs, such as happiness, excitement, excessive play, and barking. While withdrawal from interaction may signal fear or anxiety, it is not classified as aggression. Recognizing the distinct cues of aggression is crucial for handlers and caregivers to ensure safety and appropriate responses in various situations.