Taking dogs on BTS, Grab and taxis in Bangkok

I take Bua and Nemo, both small dachshunds, almost everywhere. The rules are not written anywhere clear, so this is what I have learnt from doing it for two years. BTS allows small dogs in a carrier bag or a box, and the staff have never stopped me. Grab drivers differ a lot. Some are fine, some will cancel as soon as they see the dog. I now always say the dog is in a carrier and ask first in the chat. Taxis are the hardest. Some drivers say no straight away, and it is better to just walk to the next one than to argue. Always keep a towel in the car because even a calm dog can have an accident. Nutella the koi does not travel, obviously.