I think at his size he’ll be fine with most all kibble sizes. I have a 4 pound chihuahua, a 9 pound poodle, a 14 pound bichon and a 47 pound PWD who all eat variously sized kibbles and do fine. The hardest kibble for my 4 pounder to chew is- believe it or not! Fromm 4-star. They are tiny sized, like cat kibble, but VERY hard and she takes forever to chew them. They’re so hard my poodle spits them out and won’t even bother with them.
Newman’s own is good, I’ve also had good luck with Purina 1 Beyond (yes, really!) and most recently trying Precise (Naturals line, not the holistic). All kibble sizes are well received by my guys.
Hope this helps and congrats to you!
