Not to worry! What you observed is part of the annual spawning of kokanee salmon along the shoreline of Coeur d'Alene Lake. Kokanee are a landlocked sockeye salmon and like all Pacific salmon, they die after spawning. The vast majority of kokanee spawn between mid November and the first of January along the two miles of shoreline from Higgins Point east into Wolf Lodge Bay and around the corner into Beauty Bay. Kokanee are not native to Coeur d'Alene Lake, but were first introduced in 1937 and have provided an important sport fishery with an annual harvest of up to 600,000 fish annually. They are also an important forage fish for the chinook salmon in the lake and their dead bodies attract migrating bald eagles from all over the Pacific Northwest. It is not unusual to see as 50 or more bald eagles on the north end of the lake this time of year.Drinking the water will not hurt your dog a bit, but you might not want to let him roll in a dead fish, or you will be reminded of the experience until he gets a bath.