I only know Peruvian Cuy. May not be the same thing. For Peruvian cuy, you're best off going to a pet store and buying a cookbook.
What is Nicaraguan cuy?
You might try
COMEDOR NICARAGUENSE CAMACHO
2019 W VENICE BLVD
There used to be a place on Alvarado, Managua restaurant, that had nacatamales and other nicaraguan food. Maybe somebody knows where they went...
Try Polarica Meats at 1 (800) GAME-USA. They have had it before, but their stock changes a lot. You might also search under the name nutria, another name for the same critter. They are widely available in Western Louisiana because someone started raising them for their fur, and a breeding pair escaped. The Cajuns adapted them to traditional recipes. I ate cuy several times in Peru, and they're tasty beasts, plenty of meat per pound and a bone structure that is easier to navigate than that of a rabbit. Plus four drumsticks, so the kids don't fight over who gets one...
Cuy and Nutria are different animals.
Cuy is a guinea pig, lives on dry land whereas Nutria live in the water and are a tad larger.
I want to eat both animals.
They seem like a good solution to people's desire to eat meat and the smaller spaces we're tending to inhabit. Plus you could raise your own cuy in an apartment!
Not that I would do it, just an interesting idea that I read somewhere.