Cats should not eat raw oysters. Raw oysters contain bacteria, parasites, and salt and vitamin B1-degrading enzymes that are harmful to cats, all of which cats cannot digest or process.

These factors can lead to problems such as infections and increased burden on the kidneys in cats. Although oysters contain nutrients that are beneficial to cats, such as taurine and selenium, it is best to avoid feeding them oysters to cats considering the potential health risks.
Eating raw oysters may hinder the synthesis of vitamins in cats, and even a small amount could cause illness. Oysters have a relatively high salt content, which can put a significant strain on a cat's kidneys and may increase eye discharge and tear stains.