Are you putting the bowl down for 10-15 minutes and then picking it up until the next meal time?
If not, I would do this.
Two things you could do, but GSDs are smart, and he might turn into a spaz when you open the bag. If you feed him in the kitchen, put him in his crate and then put his food down, and then release him.
Or, you could Take a can, and use it as the measure for his food and then dump it in his dish.
This can be just excitement, or it can be resource guarding on the bowl. Recource guarding is a bigger issue, and I would suggest running a search on that. You could feed him on his crate pan and eliminate the bowl, or hand feed him.
If it is just excitement, Oh MY GOD SHE HAS THE FOOD! OH PALEEEEZE GIVE ME MY FOOD!!! I'M STARVING!!! I HAVEN'T EATEN SINCE FOREVER!!! Frankly, I just try to stay calm myself. I do not make them sing for their supper or anything like that. I just put it down, and walk away.
Jenna, RN CGC & Babs, CD RA CGC HIC
Heidi, RA CGC
SG3 Odessa, SchH1, Kkl1, AD
Ninja, RN CGC & Milla, RN CGC
Joy, Star Puppy, RN CGC
Dolly CGC & Bear CGC