My last girl had her dew claws all of her life, never gave her an issue. I though Great Pyrs & TM's actually can use their "extra toes" I saw a video about it that showed close ups with gr pyrs.
As for yard work. My last girl trained me well. I will NOT EVER plant or dig in front of my pooch again, & that was 20 yrs ago. Planted the entire yard, worked from about 6am-8pm-...she "helped me dig the holes, I thought it was wonderful, all the neighbors thought it was so cute, got comments from passer-by's all day while I was working. Maybe 8pm or so, I went into the house to answer the phone & take a short break.
Not even 15 min later, come back out, the entire front yard is ripped apart-every single plant up rooted-couldn't even tell what used to be a dozen white azalea bushes, everything, not just pulled but completely destroyed-not 1 plant could be salvaged, not even the rose bushes. UGH!
My neighbor thought it was hilarious-He WATCHED the entire thing--"she helped you put 'em in, she thinks they're hers-you should know that!!!" & he laughed like hell.
His pup was 6 mos older than mine, an Akita & very stubborn, so he was rather ENJOYING my lesson.
So be careful letting them help dig anything anywhere you want to plant, because only a few min alone, just a pee run or to answer a phone can be enough time to undo all of your work.
I have since moved to things that are easy & grow fast--vines, morning glories, violas--stuff more 'dog proof' lol since I do not have a yard big enough for a separate fenced off garden.