Unified autotomy severity scoring system (0–5 scale).
| Severity stage | Unified score | Classic autotomy (toe damage) | Atypical autotomy (plantar damage) |
|---|---|---|---|
| No autotomy | 0 | No visible damage. | No visible damage. |
| Stage 1 | 1 | Only superficial skin scratches/erosion on the toe(s). | Epidermis intact; mild localized redness/swelling. |
| Stage 2 | 2 | Partial loss of a toe, or significant damage to the epidermis/dermis of multiple toes. | Partial-thickness skin loss involving the epidermis and extending into the dermis (superficial ulcer). |
| Stage 3 | 3 | Full loss of 1–2 toes, or damage reaching the bone of a single toe. | Full-thickness skin loss involving the dermis and subcutaneous tissue (deep ulcer). |
| Stage 4 | 4 | Full loss of toes, or damage reaching the bone (osteolysis) in multiple toes. | Full-thickness skin loss with extensive damage reaching the bone/fascia. |
| Stage 5 | 5 | Self-amputation of the entire distal paw, or massive necrosis/infection, making the wound unstageable. | Extensive necrosis or unstageable wound covering a large plantar area. |
This scoring system quantifies pain-related tissue damage by lesion depth on a single 0–5 scale, regardless of location (toe or mid-plantar). The assigned score corresponds to the highest observed severity stage on the paw and serves as the dependent variable for two-way repeated measures ANOVA. Application example: If a mouse has a stage 4 lesion on its toe and a stage 2 lesion on its mid-plantar region, the unified score is 4. If it has a stage 3 mid-plantar lesion and no toe damage, the unified score is 3.