Just want to say I am so sorry you and Phoenix are faced with this illness... Been there, done that, and you'll know when the time is right to make major decisions.
The end stages of renal failure are the most heartbreaking to watch. Do you remember what her BUN and CRE levels were? While your vet is correct in treating the phosphorus, that's not the only concern with renal failure. Also, can you ask your dr about increasing the fluids? Daisy was only 25 pounds and we gave her 250cc's every day for the last 3 weeks. Unfortunately, I lost her about a month ago :(
She is getting blood drawn on Saturday. Hopefully I will know more then. She is almost 14, so she has had a good long healthy life. She was never sick before this. It will be hard to let her go, but I feel better knowing that her life was not cut short.
I don't give her the fluids myself (she absolutely hates it and squirms all over the place) so, I take her to the vet twice a week, which is not easy with a full time job. I am amazed she has lived this long. I didn't think she would make it through February.
How did you know it was time when it happened to you?
When she didn't want a bite of banana, her favorite food, I looked deep into her eyes, she returned my gaze, and I heard her little soul say to me "it's time." She held on for 5 months giving me time to prepare.
Daisy suffered with kidney disease for 13 months. The last 5 weeks were the worst though - her levels went up, she was barely eating, vomiting and diarrhea then she spent 5 days in the hospital getting IV fluids, medicine, etc.
The first few days after the stay, she came home and refused to eat... settled on cat treats for a bit and had shots of cerenia twice to help with the nausea. She was never really quite the same after the hospital stay. She was very slow moving and sleepy. The last week, she threw up Tuesday - Thursday. The last bit of food was Thursday morning, took her to the vet (we had been going to monitor bloodwork every week for the last month) and her levels were up again. We knew that it was only a matter of time. The next day, she started to fidget during her fluids and I stopped them halfway through. She still wasn't eating. I knew she wouldn't make it through the weekend.
Saturday, Feb 22... she was very restless overnight, pacing, falling, etc. I knew it was time. I picked her up, rocked her in my arms and told her not to stay around for me that I'd be ok and I'd never forget her. Not a minute later, she fell when she would walk.. her back paws were dragging on the floor as she walked. My vet met us at the office to put her down. She was ready. I truly believe they tell you when it's time. Trust your sweet girl that she will let you know. I second guessed myself for a few days, but honestly, the pain Daisy was in was far too bad for me to watch.
I promised her no more hospital stays... and that I wouldn't make her suffer. She spent almost 11 years making me happy, loving me unconditionally that I knew I owed it to her to end it before things got really bad. You'll know, and you will never be fully prepared to say goodbye. I still miss my sidekick and still get sad and lonely. Take as much time as you need to grieve, everyone is different. My heart breaks for you, I know how tough it really is. I often compare it to a roller coaster ride.. one day, she could feel great the next two days she could feel worse.
Just make sure the good days outweigh the bad :( and trust in her that she will 'tell' you when she's ready.