Yes, mousedeers here are quite suspicious on species identification.
This family of mousedeers were signed "Greater Mousedeer (Tragulus napu)" and were in a separate enclosure from Lesser Mousedeer (Tragulus kanchil).
The individual in the photo is a juvenile and is about the same size as Lesser Mousedeer, but adults were significantly larger, so is probably not a Lesser Mousedeer.
Another zoochatter mentioned that it could be a Philippine Mousedeer (Tragulus nigricans), but I really don't know how they will end up in Taiping.
@Toki Looking at the throat pattern you are correct and that it is a juvenile explains my confusion on the overall jizz.... The other pictures clearly show greater mousedeer.