Q:

How can I tell if my cat is traumatized?

I had to travel for one week and couldn't take my cat with me, so I left him with the lady who helps me at home. She took him home with her. I gave her all the necessary food, litter box, and everything she'd need. I was asked her to send me daily pictures of him. She told me he was very happy, but had less appetite than usual.
After coming back, I noticed that my cat is not as happy as before. He is more afraid to love freely, and sometimes squints with one eye. I'm scared that these are signs of being traumatized or hit for any reason. How can I tell if he's been traumatized or mistreated?

A:

I think it's more likely your cat has gotten some sort of infection from being at a strange house, or maybe it is some unrelated illness. Your cat giving a vague impression of being unhappy, and having less appetite are both common symptoms of some sort of illness. So you might want to schedule a vet appointment if it continues. 
It is also possible that the cat is simply stressed out. It's pretty stressful for them to go to unfamiliar places, have their familiar humans disappear for a period of time, and be forced to live with an unfamiliar human. If it is just stress, I wouldn't expect it to last too long now that it's back home, maybe a day. 
I'm not an expert in the signs of trauma in cats, but it doesn't really sound to me like your cat is afraid. My understanding is they will either cower and hide, or become aggressive because they think they need to defend themselves. I do know especially in animals that have experienced a pattern of abuse, they might develop abnormal behaviors such as being very defensive of a particular area of their body. They might seem okay with touching, until you touch that area, and then they will suddenly pull away or even attack you. 

