Clostridium Difficile in Dogs
The reason I bring up the subject of c diff (clostridium difficile) when you mentioned Sandy is that during the hurricane the sewers and treatment facilities were flooded. Leaving homes that were flooded, streets and beaches in our area contaminated. Iam a nurse and see c diff often since it is easily transferred. The symptoms you describe fit the description.
EPA's Study of Hydraulic Fracturing and Its Potential Impact on Drinking Water Resources | US EPA
There is also a map showing the areas where fracking is common and there seems to be a lot going on in PA., unfortunately I can not find it right now but Im sure you could google it