Seth, this is a difficult time for you, and I'm sorry you're having to go through it. We lost our first dog to lymphoma cancer. I agree with Chatty, give as much comfort and love as you can and keep your little one as comfortable and happy as possible.

As for the cough, I don't think there is anything you can do to the diet to make it change. You could check with your vet to see if there's something they can give you to help sooth the dog's throat and help the cough and make her more comfortable.

Be brave. Remember we're here for you.

Peace.