Christopher S
Take your dog to the vet.

SifuGreg
They make bowls that have obstacles in them to slow dogs down. I just throw a ball or a couple of bones in with the kibble forcing the dog to navigate around for it. Dogs tend to eat around them instead of thinking to remove them first. A better solution is get a feeder ball or a tug-a-jug (). This will not only slow your dog down but add substantial mental stimulation to meal time which is very important to a working dog. Kibble Nibble: Tug-A-Jug: Buster Cube: Interactive Toys:

andy
clean it up asap. yell at him when he tries to eat it again. loud enough to scare him. and immedietely clean it up.

Will Superfly
I seen this with my cat. Your dog probably swallowed something indigestible and it is caught in his intestine. If the Throw up is Green it is probably an upper abstruction. If it Brown it is lower. And Take him to the vet immidiatley forit can even kill him.

unknown......
I agree with sifugreg he is right if you gont want to buy one of those bowls throw in a tennis ball or maybe feed him in halfs

Steve E
Feed him smaller meals more often. What dog food are you feeding maybe you need a better quality food. Maybe have him checked by a Vet does he have any other issues how is his poop any worms?

Myra
Apparently your GSD has been doing this for awhile because of the weight loss. You need to take him into your VET. My GSD is not quite two and he also eats his food fast, dry food, with out a problem. Still and all that is just my dog. Constant vomiting and weight loss is not normal so Call Your Vet.

Evan
Our dog had the same problem. The vet told us it is a breed-specific problem and most GSD puppies eat too quickly, which causes them to ingest large quantities of air that, in turn, causes them to spit up their food. He suggested a bowl with obstacles (you can buy them or just put a large rock in the center of his current bowl) and feeding smaller portions. Best of luck.