How would you word this?

[Blablabla1984]

We just bought a new house. The carpet is nice and fluffy and I really don’t want it being spoilt straight away.
My PIL have a dog that they take everywhere with them. He is also being treated as their child. If a restaurant or a shop says they don’t allow dogs, my FIL complains to the manager, leaves a bad review on Trip Advisor and so on.
So clearly they’ll bring the dog to our house… Which I am not so keen on. Is there a way to say NO in a nice way? I just think if we say something, they’ll stop visiting and will cause friction which I don’t want.
I know the dog lovers might not necessarily agree with me but it is what it is.

They'd have to visit pretty often to cause an issue to the carpet?

If you don't want it on there at all could you buy a rug to put down when they come for the dog to lie on, or use another room to sit in when they visit?

I have a dog which I take everywhere but my mum's husband has a house full of knick knacks and ornaments so she just said if you visit would you mind either not bringing him or we just meet somewhere else. I wasn't offended at all (because he is very energetic and clumsy). So I'd just be as honest as you can, they will probably understand.

I think it's odd to bring your dog to someone else's house TBH. Your house, your rules.

I'd just say 'No sorry. Only just moved in so don't want it smelling of dog and getting hair on the carpet already'.

You're just going to have to put your foot down and tell them not to bring the dog.

Your house, your rules.

This.

My PIL have a dog that they take everywhere with them. He is also being treated as their child. If a restaurant or a shop says they don’t allow dogs, my FIL complains to the manager, leaves a bad review on Trip Advisor and so on.

Your FIL is a dick

I don't actually get our dog until tomorrow, would I would never imagine being able to take it somewhere without permission.

Just tell them, no dog in the new house. Would you allow it in the garden?

If the dog is well behaved and just mooches about or sits quietly I actually wouldn't see what harm it could do the carpet.

If it's a lunatic that hares in and out, moults prodigiously and drools I would simply say, "please do not bring the dog".