I think my cat is going to leave for good...

Pappy o' daniel

Hi, I have a cat 13yo, but hasn't been able to catch rats for some time now so I decided to get a young apprentice. Unfortunately my old cat never really wanted anything to do with the new kitten I got, and now shes spending more and more time away from home. I'm afraid shes going to take off permanently and shack up with one of the neighbours.
They are both female, and theres plenty of land for both cats and the old cat is neutered.

Sigma Force

If she doesn't mind being indoors, bring her indoors more give her more attention and perhaps set up a cosy quiet place for her to sleep and enjoy her retirement. Bribing her with nice food etc. as well.

Usually when cats get older they just want somewhere extra cosy to kip.

The Sweeper

Well of course she's going to piss off. Wouldn't you, if the person you loved replaced you with a younger, fitter model?

But seriously - when you introduce a younger cat to an older cat, you need to ensure you maintain the cat pecking order. It's natural, right and proper for an old cat to put the smackdown on the young interloper - hissing, swatting, growling. If you interfere because you project your human emotions on the cats, and you want your old cat to be 'nice' to the younger one, you're effectively empowering a coup, allowing the young upstart overthrow the existing government and deposing your older cat.

The older cat, nose seriously out of joint, will almost always undergo a complete personality change, or just piss off somewhere else.

In order to reset the balance, you need to 'elevate' your older cat again, reposition her as top cat and let the younger cat find its own place in the pecking order. (Remember, a young, introduced animal expects to be bottom of the ladder when it joins a new pride, pack or flock - that's the way through nature, so they don't suffer for being hissed at and having to tiptoe about for a while.) When the older cat feels secure in her position, she'll simply start to pointedly ignore the younger cat, who'll then work on ingratiating herself until they greet each other with nose touches and live in a sort of tolerant harmony.

Also, get your younger cat neutered on the double - female cats can go into heat as young as 16 weeks (if they're well fed and healthy). If unmated, they'll continue to go into heat every two weeks and in no time at all you'll have a 13 year old cat, a six month old cat and a litter of kittens to deal with. If you don't neuter her she'll attract every Tom for miles around, and those other cats will in turn be very upsetting for your 13 year old cat, coming into her territory.

Ways to elevate your 13 year old cat: bring her indoors or restrict the younger cat's movements some so your older cat can reclaim a territory. Then gradually introduce the younger cat into that territory, and never give out to the older one if she tries to put manners on the younger one. (Obviously, if an all-out brawl ensues, intervene.) Spend more time with the older cat, greet her first, feed her first, so on.

Hopefully when the balance is restored, they'll all live together in happy harmony.

Pappy o' daniel

My cats are outdoors only.

I think my old cat has a gentle spirit, because the kitten would be pawing her and jumping on her like play fighting, but instead of putting the smackdown on her, my old cat concedes and runs off. My old cat would be trying to ignore her, but the kitten would keep after her trying to play fight. She hisses at the kitten, but the kitten ignores the warning. I have to lock up the kitten so the old cat can eat in peace.

I've begun to shout stop whenever the kitten trys to paw her, and it seems to be having some effect. When the kitten grows out of the "play fight" stage I wonder will she start showing the elder cat some respect?

The kitten is about 12 weeks old should'nt I wait until everything is "developed" before I get her neutered?

Pappy o' daniel

And by the way my cat may be 13 years old, but shes not at the OAP stage yet. She catches on average 4 or 5 mice per week. We live in the country next to wheat fields so theres always plenty of rodents.

You could say shes a Weapon of Mice Destruction

Sigma Force

Cats can be agile up to the very end but as she's getting older she might appreciate some home comforts

Pappy o' daniel

Bump, would like some more help with this, please.

Rancid

I think Minesajackdaniels has all the right ideas.

If you follow the advice given, your older cat should begin to feel the dominant cat again and begin to reclaim her territory and feel at home again.
Definitely the younger kitten has to take the hissing and spitting and it will eventually lessen and they'll begin to tolerate each other.
It will take time, though!