Cooked liver — Food safety facts
Feed with care · Cats · full breakdown on the linked food page
A tiny amount of cooked liver is fine, but liver is extremely high in vitamin A — regular feeding causes vitamin A poisoning (bone problems).
Short answer
Stick to very small amounts of cooked liver — no more than a teaspoon-sized piece occasionally. While rich in nutrients, liver contains dangerous levels of vitamin A if fed regularly. Watch for signs like lethargy or bone pain, which could indicate vitamin A toxicity developing over time.