a freshly made cup of tomato sauce on a wooden cutting board surrounded by tomatoes on a sunny day

Can Cats Eat Tomato Sauce?

Can cats eat tomato sauce? In theory yes but in practice no. It is not the tomatoes that are the problem. It is the additional ingredients such as garlic, onion, and salt that makes the sauce dangerous for cats. Read on to find out more.

Obviously, no one feeds their cat tomato sauce, that would be nuts! But sometimes things happen and you suddenly think -” hold on a minute, should my cat be enjoying that?” I had such an instance. Call me naive, but I had never owned a cat before and didn’t really know much about them. I assumed they were basically pretty bright animals and could, on many levels, take care of themselves, hence I was attracted to cat ownership. If you put food out – of any sort- they would reject or accept the food on the basis of whether they needed it or it was safe for them. I know, dumb thinking, but there you go…

Anyway, I had heard that cats like fish. So I figured I would get my cat some fish as a treat from the usual and see what happened. When it came to it, in the store, I didn’t actually know what fish to get – I just had not thought things through. So, after scanning the shelves I picked up some tinned sardines – in tomato sauce. On reflection, I have no idea what I was thinking. Why sardines and even more strangely, why in tomato sauce? Oh well. She will probably turn her nose up at it anyway if it is no good for her, was my likely thought process…

A few days later I figured it was time to see what she thought of the treat. By this stage, I had given it a little more thought, but not much, so I decided the best course of action was probably to dish out a fraction of the contents of the tin and see how things went from there. 

I am no fish eater myself – or rather not a pilchard, mackerel, or sardines man, so I was rather surprised by the odor that spread forth from the can on being opened. God, it whiffed to high heaven! However, my cat seemed to immediately transform into a “desperate and begging cat” which surprised me. I dished out some sardines in tomato sauce and within seconds of the plate hitting the ground, my cat had performed an amazing impression of a hungry dog and finished the lot off and was looking up at me expectantly for more!

Seeing how well that went I just dished out a further helping and watched the exact same response unfold again. Ok, I thought, that idea is a clear winner. Luckily for me, my cat seemed perfectly happy with the outcome and did not immediately keel over, suffer seizures and fits, and shuffle off her mortal coil!

So what did I learn? Well, I figured out pretty fast that my cat liked fish and did not seem to be put off by sauce. But did she actually like the tomato sauce? I don’t know, but there didn’t seem to be an adverse reaction in any way so all was good. 

I mentioned this new-found knowledge in passing to a relative who had their own cats a few weeks later, along the lines of a who would have known it type of conversation. Their reaction was of bemusement bordering on incredulous “what makes you think cats eat tomatoes? Have you ever seen or heard of a cat eating tomatoes before? How can you be sure you haven’t poisoned your cat?” Hmm, fair point, but still, that being said, all seems well. I figured a little research was in order. 

three tomatoes on a wicker mat viewed overhead

Can Cats Eat Tomatoes

What my research uncovered was that although tomatoes are not a natural food of the cat they are also fairly, but not altogether, benign. 

The American Society For The Prevention Of Cruelty To Animals or the ASPCA has some pretty good info on all things toxic to pets. On the matter of tomatoes, this esteemed organization basically outlines that all things tomato, apart from actual ripe, red, juicy tomatoes, are toxic to cats. 

Green tomatoes are toxic, leaves of the plant are toxic, stems are toxic – just ripe tomatoes are ok. All the other parts of the plant and unripe fruit contain a compound called Solanine. This is the bad stuff for cats (and us!). 

If your tomato is ripe it is ok for your cat. If it is raw but ripe it is ok for your cat. Cooking your tomato, whether it is ripe or unripe is of no consequence. Ripe is fine. Unripe is bad…

Just to underline that tomatoes aren’t necessarily bad for cats check out your cat food ingredients next time you get a moment. You might be surprised to see tomato listed as an ingredient. Cat food manufacturers sometimes use tomato as a filler and binder in cat food – it has the added benefit of being rich in vitamin c and fiber that can do your cat some good!

Can Cats Eat Tomato Sauce Then?

So, given that ripe tomatoes are fine and that most sauces that use tomatoes, use ripe tomatoes, that must mean if my cat enjoys the flavor of the sauce or happens to eat some sauce or ketchup with her sardines or cheeseburger side then all is fine?

No, not quite. Life is never so simple. Tomato sauces and ketchup are rarely just pure tomatoes. You have to look out for the added ingredients, specifically onion, garlic, and salt. Onion and garlic are toxic to cats in relatively low doses and salt can cause havoc with kidneys.

Take a fairly common ketchup brand and check out the ingredients in their best-selling ketchup. What you will find will be not just tomatoes but also cumin, coriander, allspice, cloves, garlic, mustard and onions, and maybe even celery and ginger. So realistically ketchup should be off kitties menu no matter how much she enjoys it on her burger!

What about the sauce that you might enjoy with pasta? Again, these are rarely just tomatoes with nothing else added. You can expect some of these store-bought and homemade sauces to contain garlic, onion, oregano, basil, and pepper. We already know that onion and garlic are a no go but did you know oregano is toxic to cats? Mind you basil is safe for cats so it is not all bad! The takeaway is that you have to be really careful with tomato sauces that you have not made yourself. Some of these ingredients are highly toxic to cats. 

a pot of homemade tomato sauce

How Do I Know If Tomato Or Tomato Sauce Has Poisoned My Cat?

Let’s say you have been growing tomatoes in your yard over the summer and kitty has become curious due to their odor and gone to investigate. In the course of the investigation, she has taken a mouthful….you know just checking texture and taste… how will you know if she has a problem and has been poisoned?

Well, if she develops a stomach upset – vomiting or diarrhea, then she has a problem but it might not necessarily be tomato-related. If she starts to over salivate, become lethargic, starts panting, or/and has dilated pupils then things are quite serious and a visit to the vet is required you should advise the vet that you think your cat might have munched on tomato plants recently.

The main takeaway from all this is that kitty will be curious and may even like tomatoes, not all tomatoes are a problem but be very careful with your cat around plants and processed tomato sauces where you haven’t checked the ingredient list. If tomatoes are ripe and sauces are made by yourself then you can relax.