Speaking with the American Kennel Club, veterinarian Dr. Laurie S. Coger, DVM, said that munching on soil can be indicative of a dog's emotional state.
Dogs have two types of cones that pick up blue-violet and yellow shades, says Lara Sypniewski, DVM, a professor of small animal medicine at Oklahoma State University.
Humans have three types of cones, " which enables us to see different shades of red, blue-violet, and green, " says Alison Meindl, DVM, a veterinarian, and professor at Colorado State University.