First off, I am sorry about Giselle, and for you. How scary!

Second, I think it is perfectly acceptable for you to ask for the bills to be covered. It is their fault their dog got loose. I know I would want to pay for ANY AND ALL damage my dog caused to someone elses property OR pets.

I would ask for proof of immunizations as well, to be on the safe side.

I also would have went to talk to them personally, because it is hard to get true emotions/expectations across through a letter. BUT nonetheless.. They should be more than willing to pay. If they are good owners, no hard feelings will come of this. GOOD LUCK! And kisses to Giselle.