Last night i woke up to my cat making a loud moaning crying sound, i first thought he was just trying to get my attention until i realized he was still asleep and making these sounds, this is the 2nd time ive heard this since i adopted him a year and a half ago. Once i gave him pets and he woke up for a second he seemed fine acted normal the rest of the day, no changes to his eating drinking or bodily functions. Was he just having a nightmare? I know cats have spasms and such but rarely hear about them being vocal like that and the fact he was an abandoned stray before i adopted him maybe he abused before or had some trauma from when he was on tue streets? Is this Something to worry about or just nightmares?