Rotti out of control

Question
Hey there,

I'm a trainer - quite new. I was wondering if you could help with any advice for my Rotti I'm training. His owners call me in for obedience for their male, 8 month old Rotti (intact). First time meeting the dog, everything goes great, he's smart, he listens, he picked everything up. Second time meeting with them the dog gets overexcited by me, tried to mount me and jumps all over, so I had to put him on a leash, that didn't help he just tried to jump at me the entire time, if I left he screamed bloody murder lunging and trying to get to me. I tried giving him a time out to calm down by himself (worked for 10 mins), I tried having the owners walk around and re-focusing the dog, worked for 1 min until he looked at me again.
Owners tell me he's never acted like this, except one time on a walk he went crazy over the leash.

3rd visit, he was FINE to say hello, he was calm so I pet him calmly, he was sitting and relaxing, so I started to talk with the owners about whats' been going on then all the sudden the dog jumps at me and claws down my face (which I was in some pain) so I get him settled, ask for a leash. I'm listening to what the owners have to say (took about 30 secs) then the dog started jumping and trying to mount me again, so I had to pull up on the leash to get him off of me and into a sit, which worked, he sat much longer. I did this a couple times then he was focused for 30 mins. After 30 mins he thought the leash was a toy, he wouldn't stop chewing on it, treats would distract him for a moment. So we tried taking the leash off, well the dog growled and tried to bite the owner (new problem!) so I bribe the dog, which works (treats for the leash) and I put the leash up high, the dog tries to jump on me again so I take his collar and he bites my arms and hands, I would describe the biting as playfully aggressive, he wanted to do what he wanted and I was preventing him from it so he got frustrated and wanted me to take my hands off his collar, his bite would get harder and harder  the longer I held onto him (cause he wouldn't stop jumping at me).

His excitement levels have turned into frustration and he's becoming out of control. He listens to me when I say sit, down, stay ect. which works to control him for the time being but if I take my eyes off him he jumps at me.He has absolutely no respect for teh owners. The owners give a command and he looks at them and walks away (when he knows sit and down 100%)

I've put him on the NILIF rule. This dog gets plenty enough  exercise and socialization. I think he's spoiled and turning into a brat.

Any advice on techniques I can use, I REALLY don't like using force but at that moment, I had to, to prevent myself from getting hurt anymore.

Answer
Find a way for the dog to be focused on the owners instead of you.  They should be holding the leash, rewarding him for self controlled behaviors.  Not sure what type of training you do, but I would have the owners clicking and treating for all 4 paws on the floor, eye contact with THEM, targeting to their hand.  He should be learning that good things come from them, not you.

This dog would qualify for Grisha Stewart's BAT protocol as a frustrated greeter.  He only gets to approach a new person when he is calm.  If you've not heard of this, check it out here:  http://functionalrewards.com/.  Not sure where in BC you are, but she's in Washington.  Find a way to get to one of her seminars if at all possible.  She's also got DVD's that would be helpful, too.

Dogs of this age need to learn that only through self control will they get what they want.  NILIF is perfect for him, but responding to cues while excited and building tolerance while frustrated will be the keys to success.

Good luck.