Having dog problems, he urinates on me, snaps and bit me last night?

I have a 3 year old chi that i adopted 1 year ago. He is housebroken. recently, he has been snapping at strangers (male and female) and visitors (mostly women and kids). I had chicken for dinner last night and when i wasnt looking, he grabbed a peice so i spanked him and he growled and snapped, so i grabbed him by the scruff of his neck and he BIT me. this hasnt happened b4. the past few days, i have been having serious problems with urination. He will sit on my lap and relieve himself. Thee is so much urine that i didnt think he would still have to go, but he continued urinating when i threw him on the floor to get him to stop peeing on me and when i took him outside he continued to pee for about 1-2 min!! then this morning, while i was sleeping, he peed in my bed! and went pee 2 more times outside. i have had to fill his water bowl more frequently than usual because its dry. is there something wrong with him or is it something i am doing wrong????

First spanking only breeds aggression, second any change in mood or behavior warrants a trip to the vet. Have him check out and if nothing is wrong enroll both of you in a training class.

Dog Diapers - Your Solution to Dog Housebreaking & Marking