My ball python hasn't eaten in 3 months. He's in a tub. He is a little over a year old. Heat lamp and heating pad on hot side around 88-90° humidity 50%
Cool side 75-80° humidity 50%
I checked his weight 1 month ago and it was 536g
I weighed him today and he weighed 524g

Is this dramatic weight loss??

He eats F/T small rats once a week
There are no signs of illness, weezing, bubbles around nostrils ect... he is acting active when I took him out