Snickers.. This cat has me befuddled

I'm really starting to think she's much older than her appearance would suggest. She is easily twice as big as her kitten, but only 1/3 the size of my semi feral tabby cat. I dewormed her, but I've seen no signs of worms in her feces. She looks as if she's starving but hardly eats. Her hips portrude up from her skin and i can feel and visually make out every bone in her spine She's also moving much more slowly and her bones .. joints ? grind when I pick her up. Her eyes are clear, her lungs are clear, her poo is normal, her belly is neither hard nor swollen, her teeth look great, no foul breath . She does sleep alot tbh when shes not in the litter box or disdainfully checking out her bowls shes asleep. Ive even found her asleep in the litter box. She has a vet appointment scheduled, but im starting to worry she may be too far gone. I flea bathed her and she fell asleep during her bath, purring at that.. once she was wet the extent of her lack of weight was horribly obvious .. her body at its widest point is about 3 inches across, maybe 4 and her skin is sunk in and tightly wrapped around bone... She has no body fat.

Any suggestions on what i can do to help her until my vet can see her? I really don't want her to die on me.
That is her sunning herself after her bath in a normal sized window.

And for comparison my thumb and finger are on either side of her protruding spine.. shes so tiny.

How soon can you get her to the vet?  The sooner the better.  Is she grooming herself? 

Her vet appointment is scheduled for september 2nd I just had her kitten into see the vet. I have called my vet and Snickers is first on the list to be seen if any appointments are cancelled, but due to being the only vet in her office, and haven taken on all of her retired partners patients she is swamped.

I haven't seen her grooming herself, but she is a secretive cat. I would assume she does, because she has hacked up a hair ball and she is/was very clean. Her skin appears healthy and her coat is soft and shiny/ not greasy or oily. I only bathed her to wipe out the flea infestation living on her.

She has no outward signs of illness, other than her lack of appetite, her lack of weight and her very sleepy nature.. I wouldn't call it lethargic, she is easy to stir and becomes alert very quickly, she just doesn't move much and falls right back to sleep.

She has dried out mostly now, she did turn around to sun her other side. Her hair is back to being dry and fluffy .. the above pictures made her look horrible. But even her long dry fur cant hide the ridge of her spine.

Can the vet give you some topical flea treatment such as Revolution before the appointment?  It does a much better job and works very quickly to keep fleas away as a preventative.  Revolution can also help with some parasites.  I would call to see if you could pick up some soon to have before Sept. 2.  Is there another vet you could find in an emergency?  Sept 2 is a very long time for an ill cat to wait.

What are you feeding her?  Have you tried different foods or even some plain cooked chicken?

Grooming herself is a good sign. 

Yes i have flea medication, I got the flea medication and the wormer from the vet when I took the kitten to be seen. The bath was just to get as many off as possible first. She literally had them so bad they were clinging to her whiskers and enough to notice would fall off when she scratched.

I feed natures variety instinct canned wet food, she also has 24 hour access to the same companies dry/freeze died cat food and their kitten food. It is grain and gluten free. I haven't tried chicken as its supposedly a common allergin to cats and she has enough issues without finding out if shes allergic.

I've been contemplating just going and buying a few cans of the junk wet food and seeing if she prefers crap over caviar so to speak.

May times, especially with cats who aren't getting regular food, fleas can rapidly cause anemia.  If she was that infested, that may have happened.

I would buy whatever you think she might eat.  Better to eat something

I agree with @Ondine, to try some other varieties.  Get some stinky Fancy Feast or Friskies.  Try different flavors.  Even some tuna in water.  She just really needs to eat.

Have you ever heard of bone broth?  It is so nourishing and helpful to ill kitties and other animals.  I have made it over and over for my sick animals.  It is chicken based, but you might want to look into it.

If you are worried about allergies, you could make the bone broth with turkey or duck, too.

You can also use Gerber baby food, stage two. Use the meat only variety - nothing with grains or veggies. Most cats can't resist it. Use it only to get something in her - there are not enough of the proper nutrients for cats in it to use it as a complete diet for her. But it may help her start eating.

Final update

Snickers seemed very lethargic monday night and I rushed her to the animal hospital. They did blood tests, several other tests and gave her fluids. The vet estimated her to be about 5 years old. They diagnosed her with advanced kidney disease and organ damage due to long term malnutrition, as well as having severe stomach ulcers which is why she wouldn't eat. After discussing her condition, pain level and possibilities of recovery with the vet, the only humane option was to have her euthanized. Snickers was put to rest yeterday at 5 pm. Thank you to everyone who offered their advice. I'm thoroughly devastated and heart broken over her, even though I only knew her a short time. She came to me to die and I'm glad that she atleast knew comfort and kindness in her final days.

So very sorry for your loss. I am so glad that in her final days she had your love.

I am so very sorry for you loss.  It is so hard to lose a beloved one.  Even though you only knew her for a short time, she was loved.  You gave her the greatest gift.  You are in my thoughts.

So sorry to hear this.  Blessings on you for helping her feel love in her life.  RIP sweet Snickers

On behalf of The Cat Site Moderating Team, we are sorry for your loss of Snickers. It is a good thing she knew your love in her last days. When a member loses a cat, we close the thread in honor of your cat and to show our sympathy and respect for your loss. You may wish to post a tribute in our Crossing the Bridge Forum. http://www.thecatsite.com/f/19/crossing-the-bridge

I am going to lock this thread now.