De or het schoothondje?

The correct Dutch article is:

het schoothondje

Rule Diminutives (-je, -tje, -pje): always het. See the rule

How to use schoothondje

the schoothondjehet schoothondje
this schoothondjedit schoothondje
that schoothondjedat schoothondje
our schoothondjeons schoothondje
your schoothondjejouw schoothondje
every schoothondjeelk schoothondje
which schoothondje?welk schoothondje?
a big schoothondje / the big schoothondjeeen groot schoothondje, het grote schoothondje