Amy, left, a basset hound who lives with her family in Bethesda, is in line for a bath - one that will make a difference for dogs an ocean away. Happy Tails, a dog spa at Tysons Corner, held a charity dog wash yesterday to raise money for sophisticated equipment - mainly cooling devices and goggles - for dogs serving with the U.S. military in Iraq and Afghanistan. The war dogs sniff out bombs, find booby traps and detect hidden enemies. At top, Happy Tails employees Chad Peddie, left, and Luz royal dry Piper, and Australian shepherd owned by Royal's mother.