We always have this “what if” discussion with owners prior to confirming a sit and insist that they have an account set up with the vet . Despite the T&Cs stating it’s a sitter’s responsibility- many sitters won’t have sufficient available funds to cover treatment upfront . If an account has been set up and we know the owners wishes we will immediately follow through, advise owners and take pet to the vet .
This is deviation from OPs topic but has been discussed on other threads