I’m going to eliminate lunch starting today and see how he does.
I forgot to stress, when you eliminate lunch, don't just spread the same amount of food over two meals instead of three. Cut back. I need to weigh Mku who will be 6 months old on Friday, but I am sure he is nowhere near 20 lbs. He is sleek and svelte and a perfect weight at the moment for his age. Lovely shape LOL.
And at risk of becoming boring, I say again, no actual treats do mine get. I measure the daily amount of kibble each morning into a container and from that container I take some with us on walks (to encourage recall) and I dip into it as a reward for particular good behaviour. Hoover and Mku think they are getting a treat, but it is not 'extra' - it comes out of their daily ration !
And I agree with DonC - what exactly started you worrying about his stools ?