My 2 1/2 year old lab has come down with some sort of cold. He is coughing and has a runny nose with green snot. We just want to know before we take him to the vets, if this is common in a dog. We have also a 5 month old puppy, who about a week ago the same thing, but it went within a couple of days and now he is bouncing around as usual. But for our older dog he has got it much worse, and i'm getting a little worried as he is not his usual self. We havnt taken either out in about a week, he is still eating all his food and drinking plenty and playing sometimes, but he is just not as bouncy as usual 
Please help 
Please help