My staffie is off her food and not herself

Rosie is 12 years old and just the last couple of months has gone off her food. She eats chicken, white fish, pasta and rice as she has pancreatitis. Even gone off her denta sticks. She has lost weight and we are very worried. Been to vets and she has had a blood test and her kidneys are fine. She also has a slight croaky bark, vet has said maybe it could be a growth on her lung but I’m not sure I want to put her through an X Ray.