My sister who recently moved to the UK with her dog, who is about 7, tells me that he is chewing his front legs to the point that they are becoming discoloured. She says he is healthy otherwise and in all honesty he should be a lot happier in his new home with far more nice places to run and swim etc and my sister being off work with him and her kids 24/7. She thought it might be down to boredom but that surprised us too. I haven't seen him so can't really comment just wondering if anyone may have had similar experiences? Not the sort of thing that hounds tend to do in my experience. I thought it may be a food allergy.

Could it be mites of some sort?

That brought back some old memorise! I had a Golden that did this, except he kept going until his legs were big sores. It essentially just a bad habit he'd got into. No vet managed to sort it out and it wasn't until after a full 3 years of this (in which time I could never show him as his front legs were so terrible, stained and with open sores) that it occurred to me to drastically increase both his exercise and obedience training. THEN he stopped. This was in the 90s so a long time ago.

Another Golden I had, recently, when he got older he licked the fur off his hind paws until they were bald. We managed to work out that he did it when it rained a lot, and it was arthritis bothering him and the wet weather made it worse.

Thanks guys, the arthritis tip could be one as he is that bit older and a large boy. Will tell her that :)

Could it be his anal glands. Someone once said that when a dog can't itch their bottoms that they transfer their biting to their front legs?

Also harvest mites are worth ruling out.

Might also be worth having a chiropractor go over him.  I've got one foot-licker at the moment but have had 3 (including her), and one of the others did it when she needed straightening out.

I've also recently seen Paige doing it and licking a raw spot, again she needed chiropractic and was really very wonky and in quite a bit of pain - you'd not know it to see her running around and wrestling with Linc but being sorted out stopped it completely (as it always did with Soli).  If arthritis is a factor it can help that too, by keeping things straight as often dogs (and us!) can become a bit out of line as we compensate for painful joints.