That vinyl stuff that is strips that are photos of wood. Is that laminate? don't know the terminology.

talk to them & tell them your concerns

you can also present various options as per above

tell them your financial situation as per above & you can remind them of their credit history too; can note no problems & you value them as a tenant...

ask them what THEY would do if roles were reversed

end up with: we can see about new carpet after the puppy is 2 yrs old.

I'm a dog person. If I moved into a new place with the expectation of getting a puppy, and dogs were OK with the landlord I'd deal with old carpet.

Why not tell them new carpets equals no pets, old carpet is ok for pets? It sounds like they didn't get a puppy yet.

ok....having been a "landlords dream" for years here's what i would expect to go down......
those carpets you posted pics of look great for a rental, a dog will mess it up here and there for sure.
imo the rent will need to be increased if you put in new carpet, obviously they aren't renting a 40 year old shanty, as the place looks fairly modern and well taken care of.

remember, PET DEPOSITS ARE NON-REFUNDABLE, so get a $300-$500 pet deposit, find the best deal you can on the carpet and have installed, and raise the rent $50 per month minimum. at the end of 2 years you'll be up $1400-$1600.......

but you'll most likely need to replace the carpets again at that time....so new carpet would probably translate to no pets....

use the existing lease as your leverage, but don't cave in.......and communicate but stick to your guns....

i would use the "give them specific multiple options" way.......they can take it or leave it.....you won't be a bad guy as they already agreed on the existing carpets and signed a lease.......kinda like buying a new car and a month later deciding you don't like the interior color and wanting the dealer to change it......

Also, remember they are in a lease. They break it, they gotta pay.

Now they could use horrible carpet as an excuse in court to get out of the lease - but you should of put it in the lease that bad carpet was accepted in placement of a pet. And if you didn't, pro-tip for the future :).

I personally don't use long term leases as my "good tenants" are month-to-month anyways and aren't going anywhere soon (I'm a "good" landlord) :). IMO, a lease really only protects the tenant if things go "bad", and in most instances don't protect the landlord for squat. At best, you might get 3 months rent from a tenant who bolts (one must mitigate the damages remember) and if one bolts after causing damages...good luck with collecting in MOST instances :(. I just cut my losses,. chalk it up as "the cost of doing business", and move on. I now have "golden tenants", but have learned a few things along the way...

If you abuse hardwood floor the cost to have it stripped and refinished is as bad as carpet. It is fishy that they start complaining right after they move in. Give them choices so that they can't say you are not willing to work with them.
Door #1: Non-refundable pet deposit and increase the monthly rent.
Door #2: Express your concerns with the puppy. Tell them that after the dog has been there a year you will inspect the carpet to see how well they kept it clean. If it is no worse for wear then you will consider new carpet. Take pictures now and then compare after a year.
Door #3: Tell them to pay for the carpet and you will give them a monthly reduction in rent for the next two years (they are more likely to take care of something they paid for). Be sure to negotiate and then put in writing up front what colors & carpet styles are acceptable and how much you will allow (no blank check). If they want the $3k carpet that's fine but you aren't paying the extra...

With a puppy no way I'd do carpet or hardwood/engineered. Tile or laminate for durability, and their rent is going up as a result.

They have a lease, a pet, and accepted the carpet when they moved in.

If they want to change the terms now, I'd tell them if they want new carpet, it will cost them $xx dollars. If it is still like new when they move out, you'll refund the $xx dollars. Incentive for them to keep the carpet nice, and you would replace it when they leave anyway.