DIY Dog Crate Question

Hello!

I’m currently building my new dog (1 year old GSP rescue) a new crate for the house and had a question. I built it out of standard common board, stained the roof and floor and painted everything else with white rust-oleum spray paint.

Is all of this okay to do in terms of the dogs health? Everywhere I read online basically said that the wood and the paint could both be toxic if ingested in large amounts but I would. Imagine if I just keep an eye out for him chewing on the painted wood I should be okay, right? Has anyone else done this and seen any issues? Could I / should I coat it in polyurethane or would that make it worse?