Support Protocol Four

Visual Assessment of Arthritis Severity

1. Hold the mouse (or rat) in a position that allows examination of the paws.
2. Examine each paw from the ankle through the digits and assign pathology score of 0 to 4 according to Table 15.5.3.

   Table 15.5.3 Visual Scoring System for Evaluating Severity in Cia Rodent Models

   Severity Score	Gross Pathology
   0	No evidence of erythema and swelling
   1	Erythema and mild swelling confined to the mid-foot (tarsals) or ankle joint
   2	Erythema and mild swelling extending from the ankle to the mid-foot
   3	Erythema and moderate swelling extending from the ankle to the metatarsal joints
   4	Erythema and severe swelling encompass the ankle, foot, and digits

3. Repeat scoring of paws two to three times a week.

Avoid excessive handling of the animals, as this can reduce the severity or incidence of arthritis.