Dog stopped barking

My 5 month old Boxer has stopped barking. He is now making this kind of groaning noise when he would usually bark. He is still eating normally and his activity level is still very high. The day he stopped barking he had eaten some grass and consequently threw up. On that day it had also gotten extremely cold in the house due to heating problems. Is this a sign of a cold? Please advise.

The best advice is to bring him to a Vet to have him checked out. It could be as simple as a cold, but it may be something more serious. It's very hard to say with certainty.

Let us know what the Vet says, and good luck.