Purina-Dog-Content-Brand Dogs are social animals and bark for the same reasons humans speak: to communicate. Dogs do bark to warn and to sound an alarm, but they also bark in response to commands and at playtime. Like people, dogs can get lonely, fearful and stressed out. Their barks often give insight into their state of being.

Researchers have studied dog barks under different conditions to assess their range of tones. Findings show a contented dog’s bark is round and harmonious. An unhappy or distressed dog, on the other hand, tends to have a repeat, high-pitched, unpleasant bark. In either case, the dog is sharing information and inviting a response from its listeners.