Border collie excess drinking???

Had our 9and a half year old BC at the vet nurse for his OAP check today. we worry about him as he had a stroke 2 years ago and had to be castrated this year due to prostate troubles...He passed with flying colours the one fly in the ointment is that he continues to drink a great deal...at a guess probably about 2 and a half litres a day????? (Approx). The vet nurse said we need to measure it so we can let them know and they can tell us if it's an okay amount,so, 2 questions for you guys..
1) what do you think would be excessive for him (he's fed dry food with water to soften it, he's exercised for approx 45 mins per day...we can't do more due to his past history)
2) How, in a multi dog household, do we measure HIS fluid intake???????
Thanks!!!
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Hiya Ailsa Personally, I don't think this is excessive at all! My old girl, will sink her head in a bucket/bowl of fresh water and drink half a pint each time no problem! The only thing I will say, is if the drinking has become excessive???? Last thing at night, I always take a full fresh bowl of water to Cassie in bed before she nods off, and she will drink from it for a good 2 minutes! I would say then, throughout any day, she will drink far more than 2 1/2 litres!
The first thing I noticed about my rescue was the fact that he's not a great drinker as I compared him to Cassie. Now that he's on steroids though he does drink more, but nothing like the amount cassie will drink. Is he quite an active dog for his age? If so, then of course he will drink quite a bit

The only way I can think of measuring it, is to pour fresh water into a bowl, keep the same bowl of water in the fridge, so it stays nice and fresh, and keep offering it to him at intervals, after exercise and food,and especially when he's heading for any of the other water bowls around the house? That's what I'd do I think? Obviously, start off by measuring the actual amount in the bowl!!!!! Doh!!

cheers H!!!!!!!
Glad to know it's not just Mo and good idea about the water in the fridge. Ta!!!!!!!!!!