Hi. I just found out that my puppy who's abt 4 months old, occassionally has the urge to vomit, just like something is stuck in his throat, but cant. Only a mixture of saliva and gastric juices is coming out that is approx 3-5cc. I tried doing Heimlich maneuver but nothing happened. He can walk short distances. He appears weak because he lost his appetite so I just prepared some water near him incase, to prevent dehydration. What else can I do for him before I will go to the vet? Thanks.