Heat the oven to 375°F. Lightly grease a small loaf pan or line it with parchment paper.
Place the grated zucchini in a clean kitchen towel and squeeze out excess moisture. This keeps the meatloaf tender without making the mixture too wet.
In a large bowl, whisk the egg with the milk and ketchup. Stir in the breadcrumbs, Parmesan, garlic powder, Italian seasoning, salt, and black pepper.
Add the ground turkey and squeezed zucchini. Mix gently with your hands or a fork just until combined. Avoid packing or overmixing the mixture.
Transfer the mixture to the prepared pan and shape it into an even loaf. Bake until the center reaches 165°F, checking with an instant-read thermometer.
Let the meatloaf rest in the pan for 10 minutes before slicing. This helps it hold its shape and keeps the juices from running out too quickly.