Answer by  
                                                                                          eaglover (394)
                                                            
                          
                          
                                                          The puppy could have a respiratory infection, kennel cough, or it could have allergies. This isn't something you want to watch for a while. The puppy would need to go to the vet asap. Just as in the case of humans, green mucous normally means that it could be an infection.