By JoNel Aleccia, health writer

What it is: Storm Defender, a fabric cape for dogs to wear during thunderstorms ($54.99 and $64.99); www.stormdefender.com

Carissa Ray / msnbc.com

What it claims to do: Keep your dog from becoming anxious and destructive during a big storm. You tie the cape lined with metallic fabric around the dog's body at the first hint of thunder and lightning – or the first sign of worried canine behavior. The makers, Storm Defender LLC of Fairfield, Ohio, claim it disperses the static electricity that builds up before a storm, calming the dog (and the owner) without the use of drugs.

My experience:  I was completely unprepared for the reality of a big dog on a dark and stormy night. I've been a cat person for most of my adult life, and happily so, until my husband and I allowed our teenaged son to talk us into a puppy. The teenager left for college, of course, and the puppy is now a 112-pound pooch with a sweet disposition – and a morbid fear of thunderstorms.

My history with felines never could have prepared me for the panting, the drooling, the whining or the sight of a giant animal standing on all four legs, looming over me as I lay in bed. A cat might slink behind a chair to quietly ride out a storm, but a dog – or this dog – insisted that everyone share her misery whenever the sky clouded over.

So after a particularly sleepless summer thunderstorm,  I decided to try the Storm Defender.  I was skeptical, but  if the makers were right, it would relieve agitation all around: "Relax, you and your dog don't have to suffer anymore!" they said.

You know what? They were right.

 A few weeks after the cape arrived, my husband and I were awakened at 4:15 a.m. by the sound of heavy canine breathing as thunder rumbled in the distance. A flash of lightning sparked a round of whining and shaking, so I fumbled for the Storm Defender, pulling it from the drawer and tying it loosely around Chelsea's neck and torso. The tomato-red cape with its shiny silver lining resembled a Halloween costume I once made for my kids, but I had to admit it did give the Lab-Shepherd mix a rather dashing air.

For the first hour, nothing happened. She paced and panted and tried to climb into the bed between us, all 6-foot-4 of her from nose to tail. I finally went out on the couch, where I fell asleep with one hand on her cape-clad back as she wheezed and trembled on the floor. When I woke two hours later, the storm was still raging, but, amazingly, the dog was not.

She wasn't completely calm, of course, but she was subdued enough to let me go back to bed for a bit. And, after a while, she grew calm enough to sleep in her own bed at the foot of ours. The next time there was a thunderstorm? Same story, only Chelsea became quieter even quicker. By the third thunderstorm – the makers say it usually takes at least three tries to notice improvement – she seemed almost grateful when the cape came out first sign of a storm.

What the experts say: "It does work sometimes; it does not work all the time," explained Bonnie Beaver, executive director of the American College of Veterinary Behaviorists.

Whether the Storm Defender succeeds seems to depend on the level of static electricity that builds up in the coats of some medium- and long-haired dogs before and during a storm.

"The static electricity starts to tingle and they begin to dread that feeling when a storm is coming," she said. "It's a learned behavior."

The cape cuts the static, Beaver explained. It may also simulate the comfort of a hug, she said.

Those theories were borne out by researchers at the Cummings School of Medicine at Tufts University who conducted two scientific studies of the Storm Defender. In the first trial, 10 out of 14 dog owners reported a moderate or good effect from the cape, while four reported little or no effect. Preliminary results of the second trial, which compared the Storm Defender with a placebo cape with no metallic lining, showed that two-thirds of dogs in both groups were calmed by the device.

But some dogs don't feel the static, or don't react to it, Beaver said. They may not be calmed by the cape because what frightens them about a storm is the loud sounds or sudden lights. For those dogs, a visit to the vet for anti-anxiety medications may be the only solution.

Bottom line: The embarrassment of dressing your dog like a magician is well worth the peace and quiet of a calm pooch on a stormy night.