Hi Elijah,
You could work with visibility conditions here.
Have the set of check boxes grouped up (for example in a container) and give the container the following visibility condition:
$currentobject/{selectyourENUMvaluehere}
This will make sure that the container with check boxes will only be shown when the user selects the corresponding vet visiting reason.
Repeat the same steps for the other options and you will have yourself a dynamic form.
Hope this helps!