Cats can eat shellfish, but in small amounts. Seafood generally has a high phosphorus content, and excessive phosphorus intake can increase the burden on a cat's kidneys and damage them.

If a cat eats too much milk-based food, it will lose its appetite and continue eating cat food. Over time, this can lead to picky eating and malnutrition in cats. Milk-based foods are also rich in calcium, which can help cats supplement their diet with high-quality calcium and other nutrients.
However, it is not recommended to feed cats too much at once, because they cannot handle too much food at once and may experience vomiting or discomfort. You need to feed them small amounts slowly.