Cats are domesticated animals that still have natural instincts inherited from their wild ancestors. Pet cats with human owners who feed them a healthy, fulfilling diet will still be attracted to other foods and may beg at the dinner table just like dogs. Cat owners are sometimes tempted to give in to their cat's begging, but not all human foods are safe for domestic cats. Seafood such as oysters has possible health risks for humans, but the risks for cats are even higher.
Oysters contain enzymes that have little effect on humans when eaten. However, cats are affected differently by these enzymes than human beings are. Enzymes contained in oysters destroy thiamine in a cat's body, especially when eaten in large amounts. Thiamine is a B vitamin cats require to survive. A lack of thiamine from eating oysters can lead to neurological disorders, seizures and comas. Even consuming a small amount of oysters may harm a cat.
Eating raw oysters is common in some areas of the world. Although some people prefer oysters steamed or fried, raw oysters are another kind of delicacy. However, the bacteria that lives in oysters can make people and cats sick. Uncooked oysters can carry Vibrio vulnificus, a bacteria that can cause stomach and intestinal problems in humans and cats. Cats can die from the diarrhea caused by Vibrio vulnificus infections; dehydration can quickly kill a cat.
Oysters live naturally in salt water oceans. Although some oysters are commercially grown, they are often still kept in oyster farms in ocean water. Unfortunately, humanity damages the ocean through oil spills, litter and other toxins we release into the world. Oysters grown in polluted water may kill cats who eat them, even if the pollution isn't strong enough to affect humans. Pollution can poison cats and cause physical damage as well as death.
Most domestic cats are fed commercial pet food diets by their owners. Dry cat food and wet cat food are created by mixing ingredients such as meat, grains and vitamins. Fish and seafood-flavored cat food are favored by many cats, who have a natural attraction to fish. However, cat food that contains oysters may have the same negative health affects as eating oysters raw. Commercial cat food with oysters may be dangerous to cats.