It's not just black cats that have all the bad luck.
Not many are aware of "Black Dog Syndrome," a phenomenon in which dogs with black fur are passed over more often in shelters in favor of lighter-colored animals.
Some say it's because of negative portrayals of black dogs in books and movies (like The Grim in Harry Potter), Dog Time says, or because their features are harder to make out. Another theory is that black dogs are harder to photograph, so they don't have great adoption photos.
The actuality of Black Dog Syndrome has been disputed. A couple studies, including one from the ASPCA, have found that coat color has nothing to do with an animal's likelihood of getting adopted.
But many animal rescue professionals insist that it's a reality.
“The effect is very real,” Mirah Horowitz, founder of Lucky Dog Animal Rescue told Slate magazine. “We recently had a litter of five very cute, very fluffy puppies, two yellow and three black. And the yellow ones all went immediately, but for the black ones it took weeks.”
Whether or not Black Dog Syndrome is real, the concerns about it are so much that a holiday was created to combat it.
October 1 has been dubbed National Black Dog Day, "to help highlight the plight of black dogs everywhere and encourage others to do the same," the website says.
People from all over are celebrating by sharing pics of their black dogs on social media.
Here's your daily dose of cuteness: