Perhaps seasonal affective disorder (SAD), a cause of depression typically seen in regions with long winter nights, doesn't just occur in people.
The symptoms of SAD are nearly identical to those of common depression, as Max Marvin, a 22-year-old Portland, OR, native, can attest: He was feeling unhappy and irritable and was struggling with insomnia, so his doctor advised him to get more sunlight exposure to boost his serotonin levels. But Oregon has minimal natural sunlight during the winter season, so his doctor suggested an artificial light therapy box designed specifically for treating SAD that produces 10,000 lux. The recommended daily "dose" of light exposure is to place the light box about 1 ft. away from yourself for 30 minutes each morning; doing so helped Marvin to get his sleep cycle back on track as well as balance his melatonin production.
When Marvin lit the light box for the first time, he noticed that his golden retriever, Luke, seemed to spend more time lying in front of the light box than begging to be taken outside. This prompted Marvin to think that Luke was also dealing with the effects of SAD. Often, pets that experience depressive symptoms are prescribed antidepressant drugs like Prozac, he explains, which can sometimes have unhealthy side effects. So Marvin, working with a light therapy device maker in England, developed a light box called the Sol Box, which is a 15-in.-tall lamp that radiates ultraviolet (UV)-filtered supercontinuum, or full-spectrum, white LED light. It is now available commercially through his company, Pawsitive Lighting (Portland, OR; www.pawsitivelighting.com).