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.

兽医劳里·科格博士（音译）在接受美国犬业俱乐部 采访时说，咀嚼土壤可以表明狗的情绪状态。

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.

俄克拉何马州立大学小型动物医学教授、兽医临床医生拉腊·西普尼夫斯基称，狗有两种视锥细胞，可以分辨蓝紫色和黄色。

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.

科罗拉多州立大学教授、兽医学博士、兽医艾莉森·梅恩德称，人类有三种视锥细胞，“因此我们能够看到不同深浅的红色、蓝紫色和绿色。”