I got a tip from a raw feeding group of a regimen of pro- and prebiotics, slippery elm and garlic-fenugreektablets that is supposed to help with this kind of issues. Chewing paws can be a sign of yeast or just boredom. If it's yeast this regimen could help...
every day for as long as it takes to see a difference..
1/2 tsp Bio Health
1/2 tsp Lacto Health
2 Slippery elm capsules
3 garlic-fenugreek tablets
My Usko licks his paws when we're away for too long, so it also can be behavioral.