Your indentation is likely messed up. Choicescript requires indentation after options. Either spaces or a tab (never mix both).
*choice
#Dog(Male)
*goto gender_selected
#Bitch(Female)
*goto gender_selected
*label gender_selected
You were a tiny ${gender} wolf cub weighing in a just one pound. You are…
For example here I indented using 3 spaces. You need to nest the contents of a command in front of it using tabs or spaces.
Edit:
I also recommend using this application, it greatly helps in coding in choicescript.