I do not know if this has been done yet but I have sent a message to the clinic, with the letter attached, asking if they can confirm the letter came from their office. I stated I knew no info about the animal or owner could be released, but just wanted to confirm the letter itself due to the lack of letterhead and the spelling error in the offices name itself.

No idea if they will reply to me, or if anyone else has been able to confirm with them that this letter did indeed come from their office.