
It sounds similar to something which happened to mine. During the foot and mouth, when walks were restricted we took them to a park we didnt normally use, and one day in particular they behaved like that. We thought perhaps the grass had been treated with some kind of fertilizer - and we did hear of the same thing happening to someone elses dogs after going to the same park. They had gone in the river, so now I've heard your tale, perhaps I was on the wrong track and it was some chemical in the water - I doubt fertilizer would be down where you have been! I used Aloe Vera gel - lots of it, as the pads did feel quite warm, bathing every half hour or so and then piling on more gel. Cant say whether it just wore off, whether the bathing cured it or the gel, but the gel did seem to stop the itch!