Once I found out how much he really *needed* to drink I took it away. He was probably 4 months old? We only bought it because we thought it would slow down his drinking, but it didn't. He'd lick the floor of the shower if I didn't close the door... sometimes when it's raining he goes outside and tries to drink the water coming out of the downspout. They say there is nothing wrong with him, medically anyway
Mentally something's not right
If they are otherwise healthy but just like to drink water, they should have 1.5-2oz of water per pound of body weight per day. Loki is 12 pounds and probably drinks at least 32 oz, and his pee is clear. So I don't feel bad taking the water away after he's had that much, even if he's begging for it. If it's hot and he's panting I'll give him ice cubes and cold water, but if he just thinks he needs more water I don't always give it to him. He just doesn't know when to stop.
Most dogs can have a big bowl of water down all day and just take a few sips at a time. Sammy does this and it's so strange to me! So, check with your vet because excessive drinking is a symptom of many diseases BUT it can also be nothing.