toys in the toybox wrote:
A ramp is a better option if they have the room and much simpler
6 risers of 6 3/8", with a run of 10", put you at 32" tall by 50" long, using the door threshold as the final riser, it'll be 60" long otherwise.
8" risers cuts it down to 4 risers and 30"-40" long depending on how you build the top riser/run. No clue if 8" is too much for the dog however.
If I were building this, I'd probably use a full sheet of 5/8" plywood ( not OSB) and cut 2 angled pieces 40" x 50" and layout the stairs and attach 2x or 5/4 cedar cleats to the plywood . Then use 2x s or 5/4 cedar, three per tread, for the run. Goes fast, isn't too expensive and you can change the stair layout if you're not happy with the riser height. If you cut stringers it's a lot more involved and it's a one time deal, can't change it very easily assuming you don't screw it up
Mill Outlet on Tyler in Tacoma has dirt cheap cedar 5/4 thick , 6' tall 4" wide fence boards. The worst ones are $1 a stick and have at least 1 good side. I've built a lot of stuff out of them - door and base trim after it was stained, shelving, temporary ladders, planters for the wife etc.