Front leg hotspots

Question
Can you give dogs a childs dose of benadryl?  My Golden Retreiver has recurring sores/hotspots on his front legs in different areas, not just where the nerve comes over the joint that the vet calls the "Happy licking spot".  I have treated the sores with Gentocin but am concerned with the long term effects of over usage.  I am wondering if he is allergic to lawn fertilizers or something else environmental.  This has been ongoing for about 3 years.  We moved from Montana to Georgia about 3 years ago and this has started since then, so it may be environmental. Thank you in advance for any advise you can give.

Answer
In dogs, benadryl has very limited use.  We use it for bee stings, fire ants, and acute allergic reactions to drugs and vaccines.  It will not work in dog skin allergies.

What you are describing are "lick granulomas."  I treat them by removing them with a laser.  These are areas of thick scar tissue with bacterial infection within.  That is what makes them itch.  The dog feels good when he licks (lick you scratching a mosquito bite) so he licks more to release the endorphins.  Some vets actually use Prozac for these.