Went here with hubby, daughter and dog last Easter (during heatwave). Fabulous. Don't think there is a dog walk on site, but the beach is literally across the road from the site and is (I believe) dog friendly all year. I spoke to one of the locals (at Rookesbury CC site funnily enough) a month or so later, who told me that the locals are very keen to keep the beach doggy friendly, and groups regularly go down there to keep it 'clean'.
In-laws went there with their dog in June and loved it also, though were a bit perturbed with the dead cow in the middle of the beach...(high cliffs and all that)