So many folks in the animal welfare sector have black animals; first they really are overlooked (there may also be more of them (??)) but from a behavior perspective consider that dogs who have the best animal interactions are often the one’s who have highlights above their eyes, around their ears and under their tails, around their butts. Black dogs not only are one color, their eyes can be difficult to differentiate from the rest of their faces – therefore dogs can’t read them from far away (or often up close).
Try getting a great picture of a black dog or cat, it’s difficult to get the lighting just right to see their eyes (and therefore appreciate the pic).
Because they’re hard to read, dogs treat them cautiously at first. This in turn makes the black dogs react in-kind. It’s tough to be nice when the people around you think you’re dangerous or stare at you.
Often by just hold-the-space for these dogs and encouraging them interactions with appropriate, friendly dogs they can get through behavior issues that may have taken root.