"These neighbors have cats.
Cats that poop in the GSHP's kid's sand box.

What to do?
I suggested painting the cats (with latex paint) or tying a ribbon around their neck.
When said neighbor complains about the paint or ribbons, you should reply that cat is pooping in the sand box and confess to painting/ ribboning the cat.

A better idea?
A less confrontational idea?

I think shooting the cats is beyond ethics. But verifying your complaint is equitable.
jC "

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

I think congratulations are in order because the neighbor's
cats as opposed to the neighbors poop in the sand box.

One must expect animals to behave as animals behave - however,
one must also recognize that a running dog will tend to get a
more visual impact than a pooping cat.

Cover the sand box. Take the pup out in the country or the beach
or a park and let the pup run. Take a frisbee, a tug, a squeekee
toy - perhaps one that tends to appear cattish - and teach the
pup the fun of fetching.

Howie52
And in needed, put up a fence.