My boys do groom their back feet and i do see them giving them a good chew occasionally especially between the toes but that is just grooming and mine never have any problems so they do groom their back feet but it shouldn't be excessive just part of the grooming routine. Another thing to bare in mind is with the wounds they have, their saliva will help heal it with any luck as most animals seem to be able to heal themselves by licking wounds although it should never be to excession again (its something i learnt a long time ago and my vet mentioned it when my cat badly injured her leg so i always assume there must be some truth to it

). I'd keep an eye on them and maybe try switching wheels around etc... and see if you get any improvement at all? Another thing is could they have been having small squabbles at all? As they are both at an age were maturity would set in, so could they have nipped at each other in play do you think? As its odd it is only affecting them and not the father!? Goodluck and keep us informed
