I don't bother with wear and tear in game because then it becomes a whole sub-game that ends up being no fun...

"Alright, I check to make sure the horse's shoes are all ok before we head out"
"Better make sure there are no leaks in our waterskins" "
"Argh, the right strap on my backpack is worn out, have to replace it"
"Is there a cobbler in town? The heel on my boot is worn out and that'll cause blisters which will reduce my movement rate and then the dwarf will make fun of me"

etc.

Pulling wear-and-tear on players when you haven't required that level of detail and attention in the past is dirty pool, IMO. And after level 1, I assume that D&D characters who spelunk are at least somewhat skilled spelunkers who know what to check for in their gear.