My 8 month old Border Collie has cuts on the inside of both her back legs- about the size of a 2p coin. They are in exactly the same place on both legs-we think this is caused by her legs rubbing together when running. Does anyone have any ideas on how to stop them from growing bigger? At the moment we have put on childs sweat bands but they are too big and keep slipping off. Look forward to reading your replies

Whereabouts on the legs are they, above the hock or below it?

Hi sorry below the hock

Do you mean "patches" then rather than cuts, as you say they are the size of a 2p coin?  Is she licking at them?  How long has she had them - did they start small and spread?

It would seem to be a bit of a design fault if a dog's legs rub together to that degree! :-)

Hi they are sort of "patches" but were bleeding yesterday and thats when I noticed them. They were bleeding again this morning after her walk, not bleeding a lot but enought to stain the fur around them. She is not licking them- she does not appear to be aware that she has them!

Just wondering - does she have rear dewclaws?

Hi, she has no rear dewclaws

"Coin shaped lesions" are a classic symptom of sarcoptic mange and I would be looking to rule that out.  Exercise might aggravate a patch of sore skin but I don't think it would be the sole cause of such a problem in an otherwise healthy dog. 

my dog also had patches like you describe, and they wher ein fact from her lying down and sitting, stopping on hard ground. if you think about it when a dog sits they take a lot of there weight onto there bent hocks and so some dogs get pressure points.