[kjc]

How old is Howie? I really wouldn't worry about him doing the tricks without treats at this point (I believe he's very young). One thing though is to change his trick routine...ie: don't do the tricks in the same order every time. Also watch for natural behaviors and incorporate those into your training. Like when he has his butt in the air, try teaching him to 'take a bow' and/or crawl... Also teach him the important things, like 'leave it' so when he does pick up an inappropriate object, you can get it away from him.

Last but not least, I'd do a quick sweep of the floor before letting him out. Eggshells can be very dangerous for dogs and can tear their insides up.

People have been going round and round for decades about using treats or not for training. I wouldn't worry too much about it at this point.