Verified answer

Cats do have emotions and traumatic experiences can stay with them. In cases where the owner has died in front of them, many cats suffer nightmares afterwards. Other highly stressful situations or experiences can cause some cats to over-groom to the point of self-mutilation.

The web site Messy Beast has lots of excellent articles about cat psychology and you'll find lots of interesting information there about their emotions, how they cope with grief etc.

http://www.messybeast.com/catarchive.htm#health

Pets have feelings and emotions. Consider this, when cadaver dogs are used at sites where a lot of people have died (think World Trade Center, Oklahoma City bombing, etc.) the dogs get very depressed when they are only finding dead people (they aren't as eager to continue searching). They get depressed and just down, so they hide volunteers amongst the rumble so the dogs get to find someone alive and then they feel better and start to search again.

A cat that has been attacked by a pack of dogs will probably be terrified by them. And yes, they dream. So I don't see why they wouldn't have nightmares.

I guess they can. I know my cat got hurt and scared once by dogs and he hid under the sofa for two days. Even with gentle talking and petting he wouldn't stay out with us.

I don't know if there is a kitty equivalent of PTSD, but the cat will definitely not forget his experience and will be shy of dogs from now on. Cats usually learn from their mistakes, unlike humans.

they dont forget my cat was hit by a car,and now will not go out

Well, it won't like dogs anymore.