excessive drinking in border collie

Our 9 year old collie, Mo, seems to be drinking a lot over the last couple of weeks. I know it's been hot, but as an example, it's been chilly here today. When we got in earlier, he drank a whole bowl of water (about a liter/litre and a half) in an hour or so. Everytime he drinks, he drinks a lot, as though he's really thirsty.
He was castrated due to prostate problems a few months ago. He's eating well and energetic and alert. His coat has been in pretty bad nick since the op, but we expected that and he's put on a little weight..not much but it's hard to tell by looking at him, the pup is so sleek and elegant and Mo is a big colllie, not one of the smaller ones.
Do you think I'm being an over anxious owner...or should we be concerned? Any ideas would be gratefully received!!!!
Axxxx

I wouldn't worry if its a one off but if he carries on I would get him checked by the vet

thanks archer, I've been noticing it on and off for a couple of weeks...one of those things y'know where you think''ahhh..he's doing that a lot today must keep an eye....'

In that case better safe than sorry...I'd get it checked

Diabetes (insipidus and melitus,) Kidney probs, Cushings disease, Liver probs are all things that can cause excessive drinking. I spent over £500 testing for all sorts of things when my dog did this, he's got "psychogenic Polydipsia" he likes to drink water!!!! Hope yours is a one off and he is fine.
Dawn.

A male Lab I was looking after a few yrs ago started drinking excessively, turned out he had a bladder infection. I`d take him the vet & take a urine sample with you so vet can test for infection & someother things Dawns mentioned

thanks dawn..you poor thing, £500 to find out he likes to drink water...nightmare!
He got a totally clean bill of health when he'd had his op (in Feb I think). He's on really good form too..running round like a young thing since his op, it's justI've noticed him drinking a lot...
Would he have any other symptoms with the other things????

Excesive drinking is an early sign of other illness so it may be worth having a word with your vet, just to be sure. Is he urinating more too, he should be.

Have to say I'm a "psychogenic Polydipsia" too but I prefer a little scotch in mine as well Sorry Azz going off subject

Norty!!
Dawn.