Hello all I truly love my dog like many of you all dog lovers out there in this forum! I have a 12 year old Pit bull Terrier, she has been aging really noticeably during the past three years! I have no plans to do any miracle work of anything in that nature but there is something on her leg, I have pictures for reference but let me best try to describe it, reason is it may be something common that your dog has had or you know someone who had a dog with this type of 'black spot.' One day, I noticed a symmetrical black spot on my dogs leg, right above the bending point on her paw it really looks like someone just got a symmetrical .5in x.5in iron and put it on my dogs paw leaving a hard black spot on her leg! It didn't bother her much but until today I saw her licking the black spot and just stopped but I'm curious if any other dog owners or maybe any veterinarians on here can chime in. At first I though spider bite, tick wound, flea wound? I have no clue, please chime in if you have any knowledge about the 'black spot.' Sincerely.