Hi Matt-welcome to the counselling service otherwise known as cockers on line!
Get your seat belt on- it could be a bumpy ride!!!
Thought I'd check in with the funny poo thing- mine was terrible on and off when I first had her (she's 17 months now).
Obviously, you should get rusty checked over by a vet due to him being very young and from a dubious situation.
In the case of my pup I did get some stuff from the vets initially but I think she is just a dog that is a bit up and down like that. Even now it does vary, she is affected by different things she eats and even in one day it might start with one or two really healthy looking samples, and as the day goes on, and with excitement etc they become looser but I tend to worry less now unless there is anything extreme as I know the dog and she is otherwise fit and healthy. You have to be more vigilant with a little pup, until their immune system has built up and you know them better.
What I will say, that can help and do no harm is a little cooked pumpkin. This can help firm the poo and they like it, so perhaps use little bits if that instead of treats?
Good luck with your little chap-hell of a first dog!!
You won't be short of lovely people to help you on here though.
See you in a couple of weeks when the biting kicks in hahahaha!
We all love our little land sharks though. They are hard work but so affectionate and funny. You will never be bored!