Feeding fish to your cat may seem as natural as a game of cat and mouse, but there are a few things to consider before you fork it over—it may not be as good for cats as you think!
- Raw fish contains thiaminase, an enzyme that breaks down thiamine (vitamin B1). Eating too much fish can cause a thiamine deficiency in cats, which leads to gastrointestinal signs (like decreased appetite and vomiting) and neurologic signs (like head tilt, falling and seizures).
- A solely fish-based diet may also lead to a vitamin E deficiency because of the relatively low amount of vitamin E in some fish. Vitamin E deficiency can cause pansteatitis, which is very painful inflammation of fatty tissue.
- The heavy metal content of fish is another aspect to consider. Because fish are bio-accumulators of environmental toxins, many species often have a very high level of heavy metals. Mercury is the most commonly talked about problem in commercially fished species. Luckily, cat foods are generally formulated using smaller, faster-growing fish species that don’t accumulate high levels of toxins, and many pet food companies test their foods for mercury. But if you’re feeding your cat fish from the fish market, you need to consider mercury to be a potential hazard.
- Fish is a common cause of food allergies in cats. Symptoms can range from chronic vomiting or diarrhea to itchy skin rashes and fur loss.
- Fish can be a slippery slope—some cats really love the taste of it and once they’re hooked, they’ll protest other, more balanced foods.
When it comes to feeding both my family and my pets, I am of the opinion that moderation is key. Unless there’s a medical condition that would make it particularly unhealthy, I’m generally in favor of treating them from time to time. That includes occasional dessert for my kids, meat scraps for my dog (not from the table—in his bowl, of course!) and a fish or poultry treat for my cats.
As with any “treat,” make sure the caloric content makes up less than 10% of your pet’s daily calorie count. Treats, like fish or even commercially prepared cat treats, aren’t part of a balanced diet. When you stray too far from your pet’s normal food, she runs the risk of dietary deficiencies or unhealthy weight gain.
If your cat eats a commercially available fish-based cat food, don’t worry. You can continue to feed this food if your cat is doing well on it, because most pet foods are formulated to be nutritionally complete and balanced. But if you’re sneaking raw fish to your cat for a daily treat or making your cooked fish her main course, you are probably doing her a disservice in the long run. Stick with commercially prepared diets and use fish as an occasional treat.