Kenchu is one of two dogs responding to merc at present (Silly boi is the other - after he had that frightful breakout of sores all over his body following Carc 200 - he probably needed a different potency ...higher I'm guessing. Too afraid to try though, as yet!).
The merc v 1m is softening his blackened thick skin. I can't yet pinpoint the exact visual symptoms that would help me prescribe to a street dog as yet.
Blackened thick eczema-like skin around the ruff or shoulder-blades, bald patches, itching dryness. These might be a good place to start.