“There’s not a lot of that type of statistics on many aspects of sheltering,” says Kim Intino, the director of animal sheltering issues for the Humane Society of the United States. “But I think that every person that has worked in a shelter can attest that in shelters animals with black coats can be somewhat harder to adopt out — or to even get noticed.”

Even after a year had passed at a Los Angeles animal shelter, no one had noticed Estelle. Except, of course, for the staff; they fawned over the big black dog and her gentle demeanor. They started letting Estelle roam the office during the day, which let one couple see her in action — outside her cage and calmly interacting with people. They fell for her, and took her home.

But not every black dog is lucky enough to get that kind of special attention, says Madeline Bernstein, the president of the Society for the Prevention of Cruelty to Animals in Los Angeles.

“They’re the hardest to adopt out, they’re in the shelters the longest and therefore, they’re most likely to be euthanized if nothing happens,” Bernstein says. (Breeders don’t tend to face this problem at the level that shelters do, simply because they have fewer animals to deal with than a city shelter that takes strays in every day.)

Bernstein has plenty of theories about why people might not want black dogs in animal shelters. It’s mostly an unconscious thing, she says, which may explain why black cats have the same problems finding a home. People who are aware of superstitions about black cats (don’t let them cross your path!) may also be unconsciously harboring superstitions about black dogs.