stayed there several years ago... Beach was okay, not fabulous... We camped there and it was a horrific nightmare... Local underage kids came thru the park and stole major items, we had one (that was drunk) throw a beer bottle at us after we caught her raiding our cooler (which resulted in OPP arresting her), trips to the bathroom involved sex-capades and marijuana smoking... Highly reccommend not camping there, but going to the beach for day use would be fine... Water wasn't clear or great but it was a major hot spell and all beach qualities were poor. It's not a nice sand beach, mix of grass, gravel and sand... but it has a nice playpark for kids...
As for dog friendly beaches, most provincial parks has dog friendly beaches....
Hope this helped...