The phrase "liver nose" refers to the color of a dog's nose, which is brown instead of the usual black. It is commonly used to describe certain dog breeds that have this characteristic.
Sentences with «liver nose»
Deeply colored individuals carry either DD or Dd genes and demonstrate either black or liver noses, lips, and eyelids. (vcahospitals.com)
White dogs may have a flesh colored nose, cooper dogs have a liver nose and black, tan or gray dogs have a black nose. (dogbreedanswers.com)
The «invisible merle» can especially be an issue if the dog actually is red (and has a liver nose). (lethalwhites.com)