My eight-year-old dog has always had big, open fore-paws which were no problem to him until about nine months or a year ago, when he began to develop new flesh on the inner sides of the digital pads, like a thickening of the pads there.  This flesh is still very soft and tender, so that he has to wear boots on both fore-paws almost continually - in wet weather because he seems to collect more grit, and now in the dry because he gets abrasions on the new flesh.  He has two now, one on each paw, half the size of a 5p coin. 

The vet sees him regularly (he's had a bit of down year, poor lad) and always checks his feet, but cannot offer any suggestion about hardening the flesh.  Because his feet hurt him, he is unwilling to exercise as much as he should, and because he can't exercise he is putting on weight.  His food intake has been reduced, and he does not think the addition of vegetables to his diet makes up for it.  He is rather a sad chap at present :( .

Has anyone experience of a similar thickening of paw pads?  I would be grateful for advice on how to get his paws back to proper working order so that he can walk barepaw and painfree again.

Has the vet swabed for infections? I tend to use purple spray or antibacterial spray sold in equestrian shops for sore feet (Iv not come across thickening pads though). Has the pavements or roads around you changed/ resurfaced?

Because of the openness of his paws, he has had a few problems with minor infections right deep inside between the pads, but with careful washing with antiseptic (dilute Hibiscrub or salt-and-water) and drying they have been cleared up for months.  But they weren't swabbed.

There's been no resurfacing where we normally walk, and the council doesn't spray weedkiller on the edges except in high summer.

The new flesh looks almost as though the pads have grown buttresses - it's difficult to describe it any other way without photos.  It's not an infective  swelling or big blister, and there's no abnormal heat in it, it's a column of flesh.  It's very soft and pink although there is a slight trace of pigment in one place, and the skin is not yet tough enough and is easily abraded if he doesn't wear boots to protect it.