Cats are fickle. Some cats love to sit next to us while we eat, watching every bite with big eyes that beg you to share. Others couldn’t care less about what you’re eating and will turn their nose up at anything you offer them.
If you have a cat that loves to share, you might be wondering if you can feed him oysters the next time you’re enjoying some.
The simple answer to this question is no. Cats should never eat raw oysters. Canned, smoked, and cooked oysters can be given as an occasional treat as long as they don’t have a lot of oil, salt, or other additives in them.
To be safe, it’s best not to give your cat any oysters. Raw oysters contain an enzyme that can make your cat very sick. Additionally, raw oysters can contain pollutants and bacteria.
Raw oysters contain an enzyme called thiaminase. Thiaminase is an enzyme that breaks down thiamine.
Thiamine is a B vitamin that helps the body break down carbohydrates and turn them into energy. The enzyme thiaminase is considered an “antinutrient” because it breaks down something our body needs.
Human beings need the B vitamin thiamine to turn the food we eat into energy. Cats need thiamine for the same reason. We don’t know why oysters need the thiaminase enzyme. Thiaminase may protect oysters and other shellfish from parasites.
When we eat oysters, we ingest a small amount of thiaminase. The thiaminase breaks down thiamine in our bodies. For humans, the amount we ingest is so small that it doesn’t affect us. When cats eat oysters the amount of thiaminase they ingest compared to their body weight is much higher.
When cats consume thiaminase, it breaks down the thiamine in their bodies. This breakdown leads to thiamine deficiency.
Thiamine deficiency is a condition that occurs when there isn’t enough thiamine in the body to turn the carbohydrates that the cat consumes into energy.
Thiamine deficiency leads to energy depletion and the death of brain cells. It also leads to anorexia-like symptoms, and left untreated, will cause blindness, seizures, coma, and death.
Cats can also get thiamine deficiency from store-bought cat foods that are low in thiamine. If the food is cooked at too high a temperature, thiamine is lost. Many cat foods have been recalled because they contain insufficient levels of thiamine.
The early symptoms of thiamine deficiency are easy to miss. Unfortunately, the condition progresses very rapidly from the early stages. It quickly causes issues like impaired vision and neurological damage. Left untreated, thiamine deficiency can be fatal.
The early symptoms of thiamine deficiency in cats include the following:
- Loss of appetite
- Weight loss
Progressive symptoms include:
- Loss of vision
- Incoordination, loss of balance, stumbling, walking in circles
As you can see, thiamine deficiency is a scary thing! You don’t want your feline friend to be experiencing any of these symptoms. For that reason, it’s best to steer clear of raw oysters altogether.
Steer clear of feeding your cat any raw fish. Lots of fish contain thiaminase. A diet high in raw fish can lead to thiamine deficiency.
Raw oysters also contain some pollutants, like heavy metals.
For humans, this is usually no big deal. Humans have large livers and kidneys that can handle heavy metals. For cats, consuming large quantities of heavy metals can damage their livers and kidneys and make them very sick.
Vibrio Vulnificus is a bacteria that can sometimes be found in raw oysters. It causes food poisoning in humans (if you’ve ever eaten “bad” shellfish and gotten sick, it might have been Vibrio Vulfinicus.)
Humans usually recover from food poisoning quickly. Cats, however, can quickly become dehydrated and die.
Smoked oysters are oysters that are steamed, then smoked, then canned. Smoking the oysters gives them additional flavor.
Because they have been cooked, smoked oysters are slightly safer than raw oysters because the thiaminase enzyme has been cooked out of them.
However, you still shouldn’t feed smoked oysters to your cat. Smoked oysters are often canned in oil, salt, spices, and all the other stuff that makes them so delicious.
Unfortunately, those delicious things make them quite unhealthy for your kitty.
Canned oysters are similar to smoked oysters. They are cooked and canned but not smoked. Depending on how the oysters are canned, they may or may not contain additional ingredients like oil, salt, and seasoning.
A brand of canned oysters that is packaged in water, that doesn’t have a lot of added salt, and that has no other added seasonings could be given to a cat as an occasional treat. It’s important, however, that you don’t give your cat too much at once.
It is safe to give your cat a canned oyster every once in a while.
Oyster sauce is a thick, dark brown sauce that looks like maple syrup. It is used in Chinese cuisine and has a rich, earthy, salty-sweet flavor. It gives dishes an umami punch.
Oyster sauce is made by boiling down oysters and their juices into a thick, briny reduction. Then, salt, soy sauce, and sometimes sugar are added. Depending on where it is made, the oyster sauce might also contain preservatives and other added ingredients.
Because oyster sauce is made from boiled oysters, it doesn’t contain thiaminase, so there is no risk of giving your cat thiamine deficiency. However, because it contains high sodium levels and can also contain sugar, preservatives, or other flavorings, it’s not a good idea to give it to your cat.
Sometimes oysters are canned in sunflower oil. Sunflower oil is non-toxic to cats, and when consumed in small quantities, it can be beneficial.
Sunflower oil contains many minerals your cat needs, including vitamins E, B1, and B5, and minerals including iron, vitamin E, vitamin B1, and B6, manganese, magnesium, copper, phosphorous, folate, zinc, and selenium. It is also packed with protein.
Giving your cat a little bit of sunflower oil from time to time is a fine idea. Don’t give your cat too much, because it can lead to stomach upset.
If you find oysters canned in sunflower oil that do not contain a lot of other preservatives, seasonings, salt, or other ingredients, you could give one to your cat as an occasional treat.
As previously discussed, oysters contain an enzyme called thiaminase that is harmful to cats. Thiaminase breaks down the thiamine in a cat’s body, rendering the cat unable to process carbohydrates for energy.
This is called thiamine deficiency. Thiamine deficiency leads to anorexia, neurological damage, and eventually, death.
Raw oysters can also contain pollutants like heavy metals. Cats can’t process heavy metals because they have small livers and kidneys. Ingesting large quantities can make them very sick.
Finally, raw oysters may contain the Vibrio Vulnificus bacteria. Vibrio Vulnificus causes food poisoning, which can be deadly to cats.
If your cat eats one or two raw oysters, he will most likely be fine. Monitor your cat closely if you discover he has eaten oysters. Call your vet if he vomits, appears lethargic, or exhibits other concerning behavior.
If your cat consumes a large number of oysters, contact your vet immediately.
In general, it’s not a good idea to feed your cat a diet of mostly seafood. Contrary to popular belief, raw fish is not good for cats. Your cat’s diet should consist primarily of vet-approved food that provides all the nutrients he needs.
That said, some kinds of seafood are safe for cats to eat as a treat from time to time.
Tinned fish, packaged in freshwater, is the best type of fish to feed your cat. Canned tuna and canned sardines are good options. Be aware that canned tuna can be high in heavy metals. Sardines are very fatty and contain a lot of extra calories.
Make sure that the fish is boneless! Tiny fish bones can lodge in your cat’s throat and choke or suffocate them. If the bones don’t get lodged in the cat’s throat, they can travel into the digestive system and cause blockages or damage internal organs.
Salmon is not a good option for cats because most of the canned and smoked salmon you’ll find at the grocery store comes from farmed salmon. Farmed salmon are often raised in close quarters and are given high doses of antibiotics to combat disease. They are also exposed to high levels of pollutants.
Shrimp that has been properly cleaned and lightly steamed is safe for cats. Remove the head, shell, and tail before you give the shrimp to your cat. Devein the shrimp. Don’t give your cat any shrimp that has been fried, cooked in oil, or prepared with spices. Don’t feed your cat raw shrimp.
Shrimp is high in sodium and cholesterol, so you shouldn’t give your cat too much at once. A medium-sized cat should eat about one-half of one jumbo shrimp in one sitting.
Cooked crab that has been prepared without oil or seasoning is safe for cats. Remove the crab from the shell, clean, and lightly steam it before giving it to your cat.
Never give your cat raw crab, as it might contain parasites or bacteria that could make him sick. Never give your cat crab shell: it can cut up his mouth, lodge in his throat, or get into his digestive system and cause blockages.
It might surprise you to learn that imitation crab is safe for cats. You don’t need to cook imitation crab before giving it to your cat because it has been pre-cooked.
As with all the items on this list, feed imitation crab very sparingly. It is high in carbohydrates and low in nutrients.
Crab sticks, crab cake, and fish sticks are safe for cats because they are pre-cooked and frozen. The likelihood of finding bacteria in crab and fish sticks is low.
Like other fish treats, they should be fed in moderation because they are high in sodium and carbohydrates, especially if they are breaded.