Best way to pay off an unplanned expense

My cat had become sick so we took him to the vet and sadly he didn’t make it. After treatments and inpatient cost the bill was about $7,000. About a month or so prior I took out a loan to pay off my debt so I don’t think I could take another loan to cover the vet cost. Someone reccommend to me opening a new line of credit and moving the balance over to the new card so I can pay it off without interest. If possible what would be the best card to go about doing this? I would only need the card as a means to pay off the balance and then I’d close the line. Any help with this would be great