What is the initial reaction of a dog to a novel loud noise, such as a gun firing?

The initial reaction of a dog to a novel loud noise, such as a gun firing, is often characterized by sensitization. When a dog encounters a startling stimulus like a loud noise, it may become more alert and responsive to that stimulus. Sensitization refers to an increased reaction to a stimulus following its presentation, especially if the stimulus is significant, unexpected, or frightening.

This heightened response can manifest as increased anxiety, fear, or even panic, as the dog may interpret the loud noise as a potential threat. The response can be more intense if the dog has a prior history of negative experiences associated with similar sounds. This initial heightened reaction differs from habituation, where an animal would gradually become less responsive to a repeated stimulus over time, and learned irrelevance, which would imply that the dog does not notice the stimulus as it is deemed unimportant. A conditioned response refers to a learned response that develops after an association has been formed, which would not apply immediately in the context of a novel loud noise.