Smithsonian has a fascinating article explaining that, yes, animals appear to get PTSD, and it has chronic effects on animals and their offspring’s health.
Inside the article is a really good, simple explanation of PTSD in humans:
“Intrusive memories of trauma, the constant state of alarm that can wear down the body’s defenses and lead to physical illness — these arise from the same ancient brain circuits that keep the snowshoe hare on the lookout for hungry lynx, or the giraffe alert for lions.
The amygdala creates emotional memories, and has an important connection to the hippocampus, which forms conscious memories of everyday events and stores them in different areas of the brain. People or other animals with damaged amygdalae can’t remember the feeling of fear, and so fail to avoid danger.
Brain imaging studies have shown that people with PTSD have less volume in their hippocampus, a sign that neurogenesis — the growth of new neurons — is impaired. Neurogenesis is essential to the process of forgetting, or putting memories into perspective. When this process is inhibited, the memory of trauma becomes engraved in the mind. This is why people with PTSD are haunted by vivid memories of an ordeal long after they’ve reached safety.”
This isn’t a “snowflake” thing. This is a brain thing. It’s real.
If you struggle with PTSD, here’s a psychiatrist and therapist near you. Talk about whether meds are right for you.
Also, Reddit has a good discussion board. I recommend discussion boards, big-time. You’d be surprised at how much you can learn and how helpful it can be, to see you’re not alone.
Finally, here’s a good site for helping someone with PTSD.