Watch it! My growl is as bad as my bite

Growl frequency patterns and bite severity in dogs appear to be linked

source: New Scientist October 23 1999 p29

Researchers have found that the severity of a dog's bite can be gauged from its growl. Tecumseh Fitch from Harvard, Massachusetts, and Tobias Riede from Humboldt University, Germany, have measured growl frequency patterns for 21 breeds. The growls of larger dogs tend to show formants that are more narrowly spaced, whatever the dog's head shape (Journal of Experimental Biology, vol 202, p2859). Dogs may assess each other's strength using this information.