
If you want to make your dog feel helpless and frustrated, give him a Kong toy.
When I first got Bijou, I bought her a
Kong toy. I figured, all dogs love these. She ignored it. So I took back to the store, happy to have $9 in my wallet again.
Then I took her to my parents' house a few months ago. She absolutely loved the Kong toy there--bouncing it around, trying to lick peanut butter out of it.
After discovering her love of tennis balls, I soon decided it would be a good idea to get her another Kong toy.

So I went to Petsmart on Sunday and shelled out the money for it again. I took it home, washed it. Put one of their free treats in it, and threw the toy at her. The treat fell out. She ate it. Started sniffing the toy, licking it. I put the other treat in the toy and set it down. Then she started to get excited. It didn't take her long to get the second toy out, because it was smaller than the opening.
So I put some chicken jerky (for dogs) into the toy. For half an hour (at least) she was frantically running around the house, clawing at the toy and chewing on it. She would sit down, stand up, sit down, stand up, run from one side of the house to the next. She was so frustrated she couldn't sit still. She wouldn't let me touch the toy because she was so intent on getting it out herself.

And how did the last bit of jerky come out? Much to her dismay, as she turned the corner--running frantically from one room into the next--the jerky flew out and she was left with an empty toy. So she had to sniff the entire house to make sure this hadn't already happened without her knowledge.
Sure, it kept her entertained and busy, constantly working. But she might have had a nervous breakdown if she hadn't succeeded in getting the jerky out when she did.
I think she can handle it, though.