My spaniel is like that,even when I bring them in the evening for a few hour's the Lurcher's chill out but that cnut just stares at me to bring him out to play fetch cnut never switches off.
There's a hare in the factories near me when a dog is on him he goes straight for the road's I've seen him doing it from what I heard a few lurchers have been killed trying to catch it.
That's the canal don it's alright for swimming the dog's but I'd be wary getting in there's all sorts dumped in it I'd be f****d if I got snagged on something.