Figure 3.

(A and B) Rats on the left show signs of facial staining, waxy yellowed skin, poor grooming, and changes in facial features possibly due to loss of facial muscle mass; rats on the right are included for comparison and show good posture, clear eyes, and a well-groomed glossy coat. (C) In addition to other signs of aging, this rat displays dermatitis at the base of the tail and extremely poor posture with rear leg splay and a dull coat. All of the rats in this figure are 24 to 25 mo of age.