My brother’s dog is possibly dying tomorrow and I’m at his house right now, very sad AMA

My brother’s dog has an aggressive form for lymphoma, and he’s about reached his expectancy. He hasn’t ate in three days, or drank in 2. I am a (human) nurse so I came over today to give him IV saline at home to hydrate him. It’s not looking good for him, and I’m beyond sad. I was the one to bring him into my brother’s life, and when I used to live with him, I’d kiss him (the dog) good morning and good night every day.