Dear …
Our little __(name of pet)__ is now gone. This has been very hard on __(me/us/our family)__ and__(he/she)__ is already so greatly missed. The absolute love and joy that we share with our pets is more that words can describe. I guess that’s what makes it so enormously tough to say goodbye.
I do know that __(I/we)__ made the best decision in allowing __(name of pet)__ to suffer no more by putting __(his/her)__ to sleep, but that doesn’t stop the tears. It was incredibly difficult to see __(my/our)__ little __(name of pet/dog/cat/etc.)__ go through the last days of __(his/her)__ life. And knowing that, you and your staff were right there for __(me/us)__. Your professionalism, care and genuine empathy shone a small ray of light through those dark moments for __(me/us)__.
I want to tell you that it was a comfort to know that you all cared. Please accept __(my/our)__ deepest thanks to you and your wonderful staff for the kind and considerate support you all gave __(me/us)__ during this terrible ordeal. Your kindness will never go unforgotten.
Sincerely,