Dog Chewing on Upper Paw Pads

Question
A few months ago, I noticed my labs paw pad on the back of his front leg above his paw was bleeding.  There was a piece of it hanging off the side.  My first thought was that he chewed it but convinced myself that he'd gotten it caught on something outside.  I wrapped it up and took him to the vet.  They cut off the loose skin, gave him an injection to fight any infection and that was it.  Of course the minute he was left alone, he ate the bandage off and thankfully pooped it out the next day.  It seemed to heal after that and I didn't give it another thought.

Now last night, I noticed some blood on our floor and checked him.  Now BOTH of his upper paw pads were chewed and bleeding.  I'm not sure what to do.  I can't bandage them because he chews them off and that can be dangerous for him internally.  The vet didn't seem to have any suggestions the last time I took him in for this.  Please help!  I don't want him bleeding all over our house and I don't know why he keeps doing this.

Answer
These problems are very difficult to solve sometimes.  What works in one case, doesn't in another.  It could be boredom or an allergy.  You could spend time at a dog park with him, take up competition such as agility, flyball, free form dancing, etc.  If he is left alone all day, doggy day care might do it.

You could press your vet for answers.  They can do blood tests for allergies, but they are expensive.  You could try a different food.  You don't need to start with an expensive grain free chow, just something different from his current food.  I have a friend whose is doing fine on lamb based Iams in place of chicken based Pro Plan.  Just a different type of meat.  Try 2-3 Benadryl capsules.  If they seem to help, it likely is allergies.  

If your vet seems uninterested in helping, you might try another.  

One last thing is the cone style collars when unattended.  They don't solve the problem, bu tmight get him through the fall to see if is is a seasonal allergy.