person A: My cat has terminal kidney failure. There's no cure.
person B: Oh_comma_ I am so sorry! I used to have a dog we loved so much who had diabetes...we gave him insulin shots twice a day but we lost him. I can relate to how you feel... 
person A: It really sucks. It's fairly common in cats and I sort of knew the diagnosis was coming but that doesn't make it any easier. I'm sorry to hear about your dog.
person B: Our pets are our family...it's not easy to see them suffer..I feel for you. And thank you about our dog.