My dog is about 2 years and i took him on his first duck hunting trip. When we got set up i let him swim a little bit, he jumped right off the boat and had a blast. When i take him to a pond he wont go in past where he can touch even if i throw treats in the water. if he jumps off a boat it doesnt bother him, but he wont go in from land. can someone tell me how i can make him swim?