Hydration

What are the signs that a dog has diabetes? The reason I ask, we recently brought into our home a four-year-old English Pointer trained for bird hunting. Mr. Big is constantly drinking and peeing, and his body temperature runs warmer than our other dog (Lab/Greyhound mix). Otherwise, he seems perfectly normal. He tends to have accidents in the house because of the amount of water he drinks. We try to limit him without being neglectful. I have concerns that he could be diabetic. Is this normal for a working dog, or should I take him to the vet? He had