Dogs may show a grinning expression when faced with threats or unsafe situations. This is their way of self-protection and defense. This expression sends a clear signal to humans and other animals that the dog does not like the situation or does not want to be approached or touched. In addition to facing threats, dogs may also display a grimace when they are in pain or discomfort.
In this case, the dog may try to avoid being approached or touched because they think it will increase the pain or Discomfort. It’s important to note that a dog showing a grinning expression does not necessarily mean that they are aggressive or malicious. Many dogs are simply expressing dissatisfaction or insecurity rather than actual aggression. Therefore, when interacting with dogs, we should respect their feelings, avoid getting too close or offending them, and help them better adapt to different situations through training and socialization as much as possible.