I would like to posit a similar story on the opposite time of year. I lived on a lake on Minnesota and we were out on the pontoon boat with my two labs. Typical hot Saturday afternoon and we were out with some friends alternating between sipping cold ones and taking a dip to cool off. My labs had learned how to climb up the ladder on their own so I could throw bumpers out into the lake and they retrieved them right back into the boat. After mindlessly throwing the bumper for quite a while the older dog, Maddie gave up and hung out on the boat. The younger dog Roxie kept going and so did I. Then she came up and pooped on the deck of the boat. I grabbed her by the collar to bring her up to the front of the boat (the little deck in front of where the people are) so she didn't mess the people space on the boat any more than necessary. Well, when I let her go she fell over and almost rolled back into the lake. I grabbed her to keep her from falling into the lake, but something wasn't right. She wasn't looking at me right - eyes were unfocused and she was not able to sit. It was like she had had a stroke. We pulled anchor and b-lined it for the house. I carried her half way to the house, put her down and same thing. We brought her to the weekend emergency vet and after I told the doc what we had been doing before the event, she told us she probably had water poisoning. The young lab would cack on water while swimming with a dummy and had been taking on a lot of water. This causes electrolyte imbalance which affects the brain. Fortunately after an overnight observation she made a full recovery, but this can be fatal or cause irreversible brain damage. SO if your dog tends to choke on water when retrieving, BE CAUTIOUS about over-working them without a break to allow them to process the water. These days Maddie's gone to doggie heaven after a full 14-year life of rooster rousting. Roxie's 9 and a great pheasant dog who is showing Dixie (5 mos) the ropes now.