We keep guinea pigs and always like to take about three with us when we go away. Most Marriott's have said this is not a problem and nothing like the problem dogs can cause (no offence to all you dog lovers, I would love a dog, but they are more of a tie). One hotel said no, we don't take pets, then asked what sort of dog it was. I replied it is a guinea pig and the duty manager said: "Oh, well that is absolutely fine. We say no to dogs mostly due to noise from barking and owners leaving poops all over the grounds".
We stay at West India Quay at Canary Wharf in London and when we went up to November they had said the GPs were "very welcome". Last November we went and the Front Office Manager kicked up a stink and said he would charge £75 for deep cleaning, despite me sending an e-mail welcoming GPs and stating that they didn't even touch the hotel fabric. In the end they refunded this after I pointed out that the room had no smell or hair residue as they stay in their own cages.
That has been our only problem and I like to think that Marriotts in the UK welcome the furry beasts as their human slaves keep them scrupulously clean (hutches washed twice a day) and are so loony about their charges that they aren't going to let them loose anyway!!! They even take towels to put down on bathroom floors so their hutches don't even touch the floor.
Personally I think all deep cleaning charges are just a way of making money and most allergy sufferers wouldn't have a problem if the bedding is clean and the carpets hoovered daily (I have a friend who had allergies to pets who has no problems with our pets and thinks it is because they are kept so clean).