Lame Cow

Got a cow that's been a little hobbled for a few days and finally caught her in the right place to get her in the chute . She has a growth between her toes on the left front . Its meaty and raw looking . Poked it and it wasn't puss filled , meaty . Wasn't on the hoof , bottom of her leg but into the space between her toes . Small marble size . I sliced it , really didn't bleed much either , sprayed some spray on it and see , not expecting any change tho . Is it some sort of fungus foot rot or am I getting the copper sulfate out ? they've been on pasture all winter and so far shes the only one . Thoughts ??????

Lame Cow