Rescue dog from hunting background keeps peeing/pooping inside – looking for advice

Hi everyone,

About three months ago we adopted our dog Brody (7.5 yrs, neutered male English Setter) from a shelter in Italy. He had lived in the shelter for about a year. Before that, he spent around six years with a hunter where he was used for bird hunting. At some point the hunter decided Brody was no longer good enough for hunting, and after he was diagnosed with Leishmaniasis, the hunter apparently wanted to shoot him. A neighbor noticed this and informed animal welfare, which is how he ended up in the shelter and eventually with us.

Brody is a wonderful and very sweet dog (can't imagine a life without him anymore), but we're currently struggling with one issue… he keeps peeing and pooping inside the apartment.

I've read through the wiki on house training, but our situation has a couple of specific complications that I couldn't find addressed there.

We think the main reason is that he previously lived in an outdoor kennel his whole life and never learned the difference between inside and outside. He has access to the garden at least ten times a day and gets three walks daily. About 75% of the time he pees in the garden without issue. On walks it's rare. He's too distracted by smells and birds, and he's not a fan of rain either. That remaining 25% is where the problem lies. Birds especially trigger his hunting instincts, and when he can't settle enough outside to go, he eventually relieves himself indoors.

We worked with a trainer who recommended blocking off the room where the accidents first happened using a steel net, since it wasn't a room he regularly used anyway. She also suggested getting him outside as soon as possible in the morning. We followed that advice, but he's since started going in a new spot closer to where we all spend time, near the couch area. The block-off approach isn't solving the underlying problem.

We've cleaned all affected areas thoroughly with an enzymatic cleaner, and we don't use a crate or tether. He has free roam of the apartment.

Do you have any tips, training ideas, or strategies that helped your dog learn the difference between inside and outside and become reliably house-trained? Especially interested if anyone has experience with former hunting dogs or dogs that spent their lives in outdoor kennels.

Thank you and all the best