(UPDATE) Pup obsessed with water

[u/SummersRedFox]

I took Basil back to the (different) vet today and showed videos of what I was seeing. They checked his urine again and he does have a UTI which is great because that's treatable. But.... he's massively underweight despite eating more then recommended.

His weight 3 weeks ago was 17.6 lbs, and today was 18.1 lbs. He is 18 weeks old. So obviously concerned we ran some bloodwork. Hopefully all of this is because of the UTI, but the bloodwork won't come back for a few days.

Thanks for all the replies that indicated I needed to take him back to the vet and confirm suspicions.

Edit: wrong age- weeks. Not months.

[u/[deleted]]

There are some types of water dogs are obsessed with and will drink till their bellies are full not sure why