Mary, I had planned to post again to offer support and to say that I too hope that you know that we are all here for you if you decide that it is Puddy's time. You will know what is best for her. But I stumbled across something tonight and I want to tell you about it. I've gone through this whole thread and I don't think it's been mentioned but please forgive me if it has.

Tonight I was researching online for ways to help make Jimmy healthier and I ended up on an IBD site that led me to another site with regard to B12 deficiency. I am so interested in this as I think Jimmy may very well be suffering from this but I was even more interested in what I was reading because Puddy popped into my mind instantly.

I will include the link to the sites but will also include some quotes below that I think could be relavent for Puddy.

What can cause deficiency of Vitamin B12 in cats? Anything that causes excessive drinking and/or urination (diabetes, hyperthyroidism, kidney disease, etc.) can deplete B12 and the other B vitamins as they are “washed out” of the body. Giving sub-q fluids could deplete vitamin B. Chronic diarrhea can also deplete B12 as most B-12 is lost in fecal matter. Cats with an inflamed gastro-intestinal tract (such as cats with IBD) may not absorb B12 properly as it’s absorbed in the intestines. Vitamin B12 deficiency can cause anemia, neuropathy, other neurological issues, etc.
Puddy falls into two of these categories with kidney disease causing excess drinking and the sub-q fluids she receives.
And the last sentence about B12 deficiency can cause anemia and neurological issues it seemed like it could fit.

Those quotes above came from this site.

Cobalamin (Vitamin B12) is a water-soluble, cobalt-containing vitamin with an important role in biochemical processes referred to as single carbon transfers. During these reactions, functional units such as methyl groups (-CH3) are transferred onto or between biologically important compounds. Cobalamin is a co-factor for at least three enzymes that carry out these types of reactions, acting as a transitional carrier of the single carbon group. A typical reaction catalyzed by a cobalamin dependant enzyme, methionine synthase, is illustrated in figure 1. Single carbon biochemistry is an area of great interest in the human population, as deficiencies in the activity of these enzymes may be associated with hyperhomocysteinemia. Hyperhomocysteinemia is a recognized risk factor for cardiovascular disease. Deficiency in cobalamin may also be associated with demyelinating neuropathies, dementia and megaloblastic
anemia (Pernicious Anemia) in human patients.
I'm not certain if this last sentence is saying that the dementia is associated in humans or both animals and humans. But since Puddy seems to have this, it was another red flag.

Cobalamin is non-irritant and may be given subcutaneously or intramuscularly, most clinicians deliver it subcutaneously
Vitamin B12 is stocked by all vets in injection form and is often prescribed to promote appetite, and help with anemia where a deficiency of vitamin B12 is the suspected cause.
And from the first site, I read that it is an option to inject the B12 into the bag of Lactated Ringers so a cat can receive it when they get their usual sub-q's. And from what I've read, it's not expensive.

The above quotes came from this site.

It's a bit harder to find symptoms for cats with B12 deficiency than people so I googled just B12 Deficiency symptoms and found these symptoms among many: (p.s. the below info came from this site.)
Nausea, insomnia, depression, dizziness, hallucinations, loss of memory and inflammed tongue! These all make me think of Puddy. She is awake all night, lying on that cool sink countertop, maybe because she is nausceous or dizzy. Her weird behaviour could be dementia or loss of memory and hallucinations. And the inflammed tongue is what really made me interested since she keeps sticking hers out. Maybe she is trying to 'cool it off' by sticking out of her mouth.

I wish I could look up more stuff but my hubby has kind of put a curfew on my computer time! LOL I feel like I'm 12. But I have been spending alot of time online lately so I promised to be off by 10:30 tonight.

I support you in any decision you make and pray that Puddy will be comfortable soon, in whatever way possible. I don't know if any of this info is of any help but I wanted to pass it along. {{{Hugs}}}