Easy! Just enter the listing of the room you’re interested in and look out for the “House rules” section - if they accept pets it should say “Pet friendly”. If it doesn’t expressly say so, it’s likely the lister doesn’t accept pets. That said, if you really like the room you could always send them a room enquiry and clarify this with the lister in the conversation.
✅ Top tip: If this is a dealbreaker for you, speed up your search by adding “Pet friendly” as a filter to only see rooms that accept pets.