There are many known foods that are safe for most humans to eat that are very harmful to kitties!
It may come as a surprise that something as seemingly innocuous as an onion or a chocolate bar can be toxic to your cat, but the reality is that many food types contain compounds or have metabolites that are extremely dangerous to cats.
(Metabolites are substances produced by the metabolism, or breakdown, of the ingested food. So, in some instances, the food itself may not be toxic, but once your kitty has digested and processed the substance, some of the resultant products may be toxic to your cat.)
Why do these foods and their metabolites produce toxicity in cats? Every species has different metabolic capabilities, but in general, the two main routes of clearing substances from the body include liver (hepatic) and kidney (renal) excretion pathways. Cat livers are not the same as human livers!
Cats, in particular, have very different hepatic excretion abilities from humans, and are, in fact, considered to be deficient in one of the most important enzymatic pathways that exists; therefore, there are many substances that we humans can metabolise and safely clear from our bodies that cats cannot, and so are highly toxic to cats.
We've put together a list of all of the common foods that have documented toxicity in cats. These are foods that you should never feed to your cat, and that you should be very careful to keep safely tucked away in cupboards and refrigerators, well out of your agile kitty's reach.
Foods That Can Be Toxic To Cats:
Chocolate - The very worst culprit! Perhaps one of the most enticing and most dangerous foods in your kitchen (to cats and human waist-lines). While dogs are much more prone to ingesting chocolate than cats, cats do eat chocolate too, and are unfortunately even more sensitive to its toxic components than dogs are!
Chocolate contains both caffeine and theobromine, both of which are called methylxanthines and are very toxic to cats. The amount of methylxanthines in chocolate varies considerably depending on the type of chocolate, but the general rule of thumb is that the darker and more bitter the chocolate, the higher the concentration of the toxic principles.
Chocolate toxicity can cause diarrhea, vomiting, lethargy or hyperactivity, elevated heart rate, tremors, and even death.
Coffee & Coffee Beans - As you have already read above, caffeine is classified as a methylxanthine and is very toxic to your cat.
Symptoms of coffee toxicity will be similar to those listed under chocolate toxicity, and so always be wary of where you have located your coffee mug and your coffee beans! Don't let your inquisitive kitty try to achieve a caffeine high, because it will have detrimental results.
Onions - While onions are extremely tasty and are quite healthy for human consumption, the opposite is true for cats!
Onions belong to the plant genus, Allium. The toxic principle in onions is N-propyl disulfide, and it damages cats' red blood cells. The destruction of red blood cells in this manner results in hemolytic anemia, and it occurs if cats eat onion in any form: raw, cooked, or powdered onion.
Clinical signs include vomiting, lethargy, and pale gums.
Garlic - Although garlic is a great asset to human health, the same cannot be said for our kitties!
Garlic is also a member of the Allium genus, and has similar, although less potent, toxic effects as its big brother the onion.
Symptoms of garlic toxicity are the same as listed above for onion toxicity.
Citrus (Orange, Lemon, Lime, Grapefruit) - Citrus fruit make a lovely snack, and are also a tasty flavor addition to any human meal, but citrus is toxic to cats.
Citrus fruits contain essential oils and psoralen toxins that cause vomiting, sometimes light sensitivity (photosensitivity), incoordination, weakness, depression, tremors, and seizures.
Moldy Foods - Moldy, spoiled foods are a danger to everyone in the household, but cats that may snoop around in kitchen garbages are going to be at higher risk for the ingestion of these toxins than human household members.
Moldy foods can contain toxins such as penitrem A, roquefortine C, and verruculogen that are produced by fungi. These toxins can cause vomiting, anorexia, tremors, incoordination, seizures, and possibly death.
Alcohol - Alcohol and kitties should never be mixed! Alcohol toxicity can result in vomiting, incoordination, stupor, depression, and sometimes coma, seizures, and death. Always make sure to keep your wine glass safe out of reach from your kitty.
Avocados - While avocados are considered to be a miracle fruit for humans because of their many health benefits, it is best that you not try and share these benefits with your cat.
Avocados contain a toxin called persin; while persin can cause death due to cardiotoxicity in birds, rabbits, goats, and even in dogs when avocado is ingested in significant quantities, there is no documentation to support that this occurs in cats.
However, there is evidence that avocados will cause gastritis in our feline friends, which may result in symptoms of anorexia, vomiting, diarrhea, and lethargy. And since we cannot be certain that avocados do not cause cardiotoxicity in cats as well, it is advisable to keep these fruits and all guacamole far far away from them!
Grapes & Raisins - While there is not yet any evidence of grape and raisin toxicity in cats at this point, it has been recently discovered that an unknown toxic principle in grapes and raisins can cause acute kidney failure in dogs.
Even though there is no documentation of similar occurrences in cats at this point, since there is much to learn about grape & raisin toxicity, it would be wise to keep your cats away from these tasty little fruits. Until we know more, it is best to err on the side of caution.
To read more of Dr. Ko's articles, please visit http://www.catdoctorko.com
The information provided in this article is for educational reference purposes only. It is not intended to be a substitute for the advice and care of your veterinarian, nor medical diagnoses or treatments. All questions regarding your cat's health should be discussed with your veterinarian.
