AN UNLEASHED DOG BIT A 5 YEAR-OLD BOY AT RIO DEL MAR BEACH ABOUT 12:30 TUESDAY AFTERNOON. THE MALE, BOXER-AUSTRALIAN SHEPHERD MIX WEIGHING OVER 50 POUNDS REPORTEDLY RAN UP TO THE BOY AND GRABBED HIM BY THE HEAD. THE BOY WHO IS AN APTOS RESIDENT WAS TAKEN TO A LOCAL HOSPITAL WITH SEVERE INJURIES TO HIS HEAD, NECK AND ARM. THE DOG WAS EUTHANIZED SHORTLY AFTER THE INCIDENT.