Salt is as bad for dogs as it is for humans. A little is fine, too much can cause problems.
Dogs that ingest too much sea water usually have vomiting and perhaps some diarrhea afterwards, but if they are allowed to continue playing and swallowing sea water (and the same goes for regular fresh water, as well) they can cause dangerous and potentially life threatening shifts in their electrolytes.
BotXXXXX XXXXXne, it's great expercise, but the dog should be supervised so they don't overdo it.
By the way...I'm a big fan of Tollers!
If you feel my answer was helpful, please click on ACCEPT. Feedback & Bonuses are always welcome. If a deposit has been made, it remains with Just Answer until you press ACCEPT. Once you press ACCEPT then I am paid.
If there is something I can further clarify, Click REPLY. Our dialog continues even after you click accept, I want to be sure your question is fully answered.