prevent my outdoor/indoor cat from becoming wild?

Does your cat have all of his shots? Probably has rabies. Indoor/outdoor cats do not go "wild". But you need to neuter your cat and get all his shots. Get him a collar so that people know he has a home. Also, teach your cat to come to a loud whistle. That way, when he is houses or streets away, he can hear you when you call. Just whistle when you feed him and eventually he'll get it.

He won't become wild trust me, I had an outdoor/indoor cat, she was semi-feral when we got her as a kitten, but she became the most loving cat and we had her for 19 years!

Maybe at the time that you were about to pick him up he had spotted something he didn't like the look of such as another cat or animal that you didn't spot. Cat's generally don't run away unless they are mistreated, get hurt and can't make it home or get lost and can't find their way back. Some cat's can be gone from home for a few days, but they do eventually come back. Male cats tend to stray away from home more than females, especially unneutered males. Just don't worry, he won't become feral.

Has your cat been neutered? If not, then he is nothing but a tom cat and ready to travel miles to mate and get into fights to kill other males for territory and mating right.

You DO NOT pick up the cat by the "hairs" on the back of the neck! You SCRUFF the cat by grabbing onto the loose SKIN not hair!

https://www.youtube.com/watch?v=FWFKl_rSpM8 - this is how you scruff a cat!

If hairs on his back were raised it is because he was terrified and ready to do battle with whatever he was in stand off with outside when you called. Beware of the raised hairs on the back (usually the tail hair puff out as well). You grab a cat in that condition he is read to kill to defend and someone grabbing him is considered an attack and it's lucky he didn't shred you!

I'm pretty sure you haven't taken into consideration everything that can happen to your cat or you'd have know what was up with the raised hairs. If he gets into fights, gets an infection or catchs FIV or FeLV from sick cats then his death is on your shoulders.

WHY CATS SHOULD NOT BE OUTDOORS

1. FIV and FeLV (FeLV kills in a year) Vaccinations are NOT 100%.

2. They fight with other cats (bites become abscesses and unless treated they die)

3. Cats eat snail bait in yards and garden and die

4. Cats eat rodents who have been poisoned and they die from the poison too

5. Cats lick up antifreeze (sweet tasting) that drips from cars and die horrible deaths (no cure)

6. Cats get killed by dogs, coyotes, and hawks.

7. Cats go to the bathroom in other peoples yard and the neighbors call animal control to take cats away and kill them or neighbor traps them and dumps them in the country to die

8. Teenagers, shoot, stab, and set fire to cats for fun

9. Indoor cats don’t get lost or stolen (“Bunchers” grab cats to sell for medical research)

10. Indoor cats live 15 – 18 years. Indoor/Outdoor cats live approx.. 6 to 8 years. Outdoor cats live 4 to 6 years. There are always exceptions however these are the averages.

Indoor cats don’t get run over.

11. People grab kittens/cats to feed to their pythons & to use as bait in dog fighting rings.

12. Very pretty cats will be stolen and kept just because someone wants it.

CATS ARE NOT DISPOSABLE ENTERTAINMENT!