Dog owners who spend stormy nights struggling to sleep while a panting, drooling, trembling pet climbs around on them know the fear of thunder can be tricky to solve. Potential remedies include medicine, desensitizing the dog to thunder and training it to retreat to a safe place when a storm hits. There also is canine "thunderwear” such as earmuffs, head halters and swaddling attire that can help calm dogs. Researchers haven’t figured out what’s behind thunderphobia. Among the theories: Some dogs may be genetically disposed; others may have learned to be afraid after having a bad experience during a storm. Some may be acutely sensitive to any sudden, loud noise; some fear thunder and no other sound. Dogs’ problems with thunder often do not become apparent until they are 4 or 5, said Dr. Victoria Lea Voith, a professor of animal behavior at the Western University of Health Sciences veterinary school in Pomona, Calif. It’s unclear whether owners fail to notice a small amount of anxiety building over time or whether the phobia didn’t start until the dog was several years old, she said. The severity of a fearful dog’s reaction also varies. Some are mildly anxious. Some pant, quake, drool or become almost catatonic. In severe cases, dogs become frantic and break through windows, claw through paneling or run into traffic if left alone during a thunderstorm. Dr. Michael Fox of Minneapolis, a veterinarian who writes the syndicated newspaper column "Animal Doctor,” suggests trying to desensitize the dog by playing a recording with storm sounds: Switch it on and let the dog "freak out” for about a minute, then switch it off. Let the dog settle down. A few minutes later, switch it on again for 30 to 60 seconds, then switch it off. Repeat it about five times at intervals of 10 minutes for four or five days, then repeat it a week or two later, he said. Fox and others theorize static electricity and changes in barometric pressure also may disturb dogs. That may explain why some dogs seem to detect storms before people can and why some dogs that panic when it thunders at home are fine in the car, or retreat to the bathtub or shower when a storm hits, said Dr. Nicholas Dodman, a veterinarian and head of the animal behavior program at the Tufts University veterinary school in North Grafton, Mass. Dodman experimented with two capes: one with an antistatic lining, the other without. Owners reported both capes helped their dogs, though the cape with the lining helped more. Dodman suggests training the dog to go to a safe place during storms. The owner should initially stay with the dog and offer treats and training to reinforce that it’s a pleasant place. Swaddling a dog also can help. It can be as simple as wrapping the dog in a light blanket or towel. Other options include anti-anxiety medicines.