I think this is a common worry among all of us. Even though I've made arrangements, I still worry. I'd considered adding PTS instructions to my will for quite a few of my babies that are so handicapped, or need constant medical attention. But fortunately my new husband said not to worry. He, with the help of my sister, will take care of them.
However, I did set up a plan with my sister should my husband & I go at the same time. If my sister survives me (we're identical twins, so who knows) she'll take over completely with the help of her hubby-to-be. He loves animals as much as we do and is the process of starting his own rescue sanctuary for cats/dogs near his home in Scotland. After that one is finished he will set one up here in Texas. For years now, he's been adopting the horribly abused animal cases televised on the news in Great Britain. They both said they will do whatever is necessary to care for my little ones.
I definitely agree with GabrielBlindDeafPupFamily about doing something now to ensure their future and ease your mind. Talk with relatives, friends, sanctuaries, vets, etc. and find people who'll help and if you can set up some kind of financial plan to ensure their care it'll be even easier. A term life insurance policy with them as beneficiaries with a designated caretaker, a trust fund, or even a savings account. Anything will help. You'll have to guesstimate how much they'll need per month over how many years, etc. It all depends on who you entrust their care to and where they will live. Then it needs to be put in a will, or something legal. You could research the net on how to write your own will, and make sure your a trustworthy friend or family member has a copy. My second husband was an attorney so I learned there's a lot we can do ourselves if you just look up the laws, rules as per your state, country. I think I'll spend some time and see what I can find. I think this is a very important subject that needs more investigation. Is there a place on this forum where it's already been addressed?
"When a child loves you for a long, long time...REALLY loves you, then you become Real." " Does it hurt?"
"Sometimes..When you are Real you don't mind being hurt."
Words I live by from "Velveteen Rabbit"