Q: My husband began taking Winchester, our 5-year-old Labrador retriever, hunting with him this season. Win seems too young to be going deaf, but I’m convinced his hearing isn’t as sharp as it was before hunting season. Could the gunfire have damaged Win’s hearing? Can it be tested? A: Yes, any loud noise can damage a dog’s hearing. Hunting dogs and those involved in police and military work are most often affected. Two factors play a role in hearing loss: the duration of exposure to the sound and its intensity, measured in decibels, abbreviated dB. Gunshot noise ranges from 120 to 190 dB, depending on the firearm. Sustained exposure to 90 dB or more leads to hearing loss. Even brief exposure to 140 dB can cause permanent damage. If you want to have Win’s hearing tested, ask your veterinarian to refer you to a neurologist for a BAER—brainstem auditory evoked …