How much fish-based cat food is too much?

January 7, 2011 2:55 PM

How much fish-based canned cat food is too much, for a cat who eats both dry and canned food?

We feed our cat both dry food (Orijen, mostly chicken-based) as well as canned food (Weruva and Tiki Cat). Both brands of canned food have a lot of fish-based varieties, as well as some others. We've been basically buying "one of each" and rotating through them, but that results in him eating a lot of fish, and I've heard some vague statements that this can be bad. I've gotten mixed answers when I've asked people about it.

He seems to like all of the varieties equally (he really loves them all, unlike many other brands), so it wouldn't really be a problem to adjust the proportions by buying more of the non-fish ones, but if it's not necessary, I'd rather not (mostly because it adds complexity for us in planning how much to buy and how to rotate it).

I'm curious, does anyone know the truth about whether eating a lot of fish-based canned food is bad for a cat, and what the rough threshold is? Should we be doing 3/4 non-fish? Is 1/2 and 1/2 ok?

FWIW, I've already done a lot of research and reading on canned vs. dry food -- I'm not especially interested in debating that further at the moment :)

posted by sharding to pets & animals (4 answers total)

What I have heard is that feeding your cat canned tuna fish regularly is bad for them- I've never heard anything about fish flavored cat food. This is only one anecdote but our family cat lived for 19 years and would not touch wet food unless it was seafood.
posted by BuddhaInABucket at 5:20 PM on January 7, 2011

Our vet warned us against feeding our cats too much fish-based wet food as we were dealing with Melon's second urinary-tract blockage. She said none of the cats should have too much fish, but specifically our blockage-prone boy. Something about the magnesium? I am not sure. But I have been told this by this vet, and then a few months later this was repeated to a friend with regards to her cats, male and female, and their vet is one of the most reputable in Buffalo.
posted by oflinkey at 5:59 PM on January 7, 2011

Thanks. I also emailed both food manufacturers, and they gave very helpful and detailed replies. I don't really feel comfortable reposting them here without permission, but I found both companies to be extremely responsive. Petropics (manufacturer of Tiki Cat) specifically mentioned magnesium, and said all their foods are low magnesium and approved for special diets for cats with special diets (CRF, Diabetes, Kidney and Liver Diseases, etc.). They also recommended this book, which I just ordered: Your Cat: Simple New Secrets to a Longer, Stronger Life.
posted by sharding at 6:07 PM on January 7, 2011

I trust the work of Dr. Lisa Pierson - the advice on her website helped my cat lose weight. She has this to say about fish:

"Fish and beef are fairly common food allergens in the cat and can cause inflammatory bowel disease and skin allergies in some cats. Think 'feathers and long ears', not 'horns and fins'.

Fish is also more apt to be contaminated with heavy metals and PBDEs. PBDEs are fire retardant chemicals that have a possible link to hyperthyroidism. Because fish is so palatable to most cats, many cat foods do contain some fish so be careful to read the labels.

If you want to feed a fish-based food as a treat, please limit it to once or twice a week. (That said, I do not feed my cats any fish on a regular basis. Luckily, most of my cats don't even like fish.)"

Full page here. The rest of her site is interesting, too.
posted by analog at 6:46 PM on January 7, 2011 [2 favorites]