My lab from the start was very energetic and very eager to play fetch. Loved playing fetch down the hall and eventually moved up to a paint roller in the backyard. Always limited our sessions to a max of 10 retrieves at the most 20 yards, and always left him wanting more. At four months he quickly lost interest and no longer wanted to retrieve. Took a week break before trying again and kind of showed more interest. Still slow over then next two months, but recently his interest has peaked again and wants nothing more than to play fetch. That being said he is so excited when playing he has started to bark before the throw. As soon as I throw he stops and goes to retrieve with no further barking. Ideally I'd like him not bark for obviously reasons, but don't know how to go about correcting this behavior with out discouraging him and losing progress. Do I ignore this behavior until he is older or are their methods to do so with out being discouraging.