Categories: Cat Healthpoison

Toxic to Cats

Onions are toxic to cats - photo by Jim (Flickr)

August 2010: A lot of things are toxic to cats or it seems that way. I wonder if more things are toxic to cats than humans. I don't think so. We just have to think more about what is toxic to cats as we are their caretakers. That said, personally, I have never been confronted with a case of a substance being toxic to a cat other than flea treatments.

On one occasion many years ago, I used a spray on my Missie. She licked it and foamed at the mouth - straight to the vet. She was unharmed but never again. "Spot on" flea control products (putting a drop on the skin) can be very poisonous if we don't read the instructions and for example put a flea treatment made for dogs on cats. That can lead to permethrin poisoning. This can kill the cat and causes severe tremors, salivation and seizures in cats.

I have already mentioned poisons.

Flea Treatments

We should take great care when applying chemicals to our cat by reading the instructions. It is interesting to note that the instructions include a reference to how the flea treatment can cause irritation (and worse?) on our skin! What about the cat? See also Flea Treatments Can Kill.


I have built two pages on this some time ago: Plants poisonous to cats and also Houseplants poisonous to a cat). This page mops up some of the lose ends to make the list complete.


Here is a list of foods that are toxic to cats: Alcoholic beverages, Avocado, Chocolate (all forms), Coffee (all forms), Fatty foods, Macadamia nuts, Moldy or spoiled foods, Onions, onion powder, Raisins and grapes, Salt, Yeast dough, Garlic, Products sweetened with xylitol.


Pop-top cans may be lined with a chemical that is poisonous to cats and humans (potentially). This is a problem that exists in Europe, the USA and quite likely elsewhere. The Independent newspaper reported on this, recently (April 2010). The authorities in Britain have said it is OK. The USA is more concerned about it.

The chemical is bisphenol-A. This chemical may cause hyperthyroidism in cats. A 2004 study reported in the AVMA Journal (Edinboro, et al.) showed a correlation between the use of pop-top cat food cans and the subsequent development of hyperthyroidism.


Lawn care chemical, 2-4-D, 2,4-Dichlorophenoxyacetic acid (2,4-D) is a common systemic herbicide used in the control of broadleaf weeds. It is the most widely used herbicide in the world, and the third most commonly used in North America1.

This chemical is used to improve lawns. Cats go on the lawn and then lick themselves. The chemical may cause health problems in cats and humans such as cancer (lymphoma in dogs and humans). Personally, I would not mix lawn treatments with outdoor cats.


Insecticides can harm cats. Cats are sensitive to chemicals used in insecticides such as organophosphates and permethrin - moreso than dogs. These chemicals can be found in garden products. Great care, it seems, needs to be applied when dispersing these products if there is a cat in the family who is allowed out.


Please read Joyce's article on mothballs poisoning cats. Mothballs are very toxic to cats. We lost 4 cats in one week by mothball poisoning.

Cleaning Products

Phenols, chemicals in some floor cleaning products can be toxic to cats. In the USA these products include: Lysol and Pine-sol. Cats walk on freshly cleaned kitchen floor that has not been rinsed and dried. They lick themselves clean and ingest the chemical. Bleaches causes salivation and vomiting due to ulceration.

Rat and Mouse Poison

Rat or mouse is killed by a poison laid down by cat caretaker. Cat eats rat or mouse. Cat is poisoned. Read more: Will rat poison kill a cat?

Pain Relief

Don't administer pain relief to cats without strict veterinary supervision. See Feline Pain Relief. For example, aspirin in toxic to cats.

Fabric Softener

This is called "Ammonium disinfectant" Causes vomiting, diarrhea, neurological depression, seizures.2

Antidepressant Drugs

These cause vomiting, lack of balance, tremors, seizures and irregular heartbeat.


In improperly glazed bowls and poorly manufactured toys for example. Poisons the cat cans caused vomiting, muscle spasms, hysteria and blindness.

Gasoline, solvents, paints

Poisons the cat.


Cat Antibiotics can cause an allergic reaction

Cancer caused by cat vaccinations



2. The Veterinarians' Guide to Your CAt's Symptoms

Major source and guide:

From Toxic to Cats to Cat Health

Comments for
Toxic to Cats

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Dec 07, 2011 cats and mall balls vs. christmas trees
by: Anonymous

I am so glad i came across these comments. I Had googled how to keep cats out of our christmas tree and among a few other things, it came up hanging moth balls.. Today i went and bought not one but two boxes. My tree is trashed and they have even knocked it.over on my head and practcaly knocked me out. I Will not use them now because after further research i realize i could lose my animals. Thank you for reminding me that just because one person says its fine dosnt make it true..Heather

Aug 28, 2010 I agree Joyce
by: Ruth

You are so right Joyce.
Around Christmas time we always get a lot of questions about how to keep the cat from climbing the Christmas tree. These people have no thought that it's the cats Christmas too and to make the tree cat friendly.
It always worries me the number of people 'advising' the asker to hang moth balls around the bottom of the tree !

Aug 26, 2010 Mothballs
by: Joyce Sammons

Be careful when you read something is safe because it may not be. I read an article yesterday on a site that recommended lining flower beds with mothballs to deter cats. Always research something you're not sure about

Aug 09, 2010 Flea treatments etc
by: Ruth

Keenpetite I'm so sorry for the loss of one cat and the illness of another.
Even buying medication at the vets instead of other places these days isn't 100% safe and it scares me a lot.
Most vets here recommend a drop on the back of the neck flea treatment monthly in the Spring and Summer but that to me is overkill and putting too many chemicals on the cat. Now there is drop on the back of the neck worm treatment too !
We usually do our cats once, in the Spring and they've been flea free this way for years. This year there was no sign of fleas so we didn't do it at all and they've never been bothered with them.They are groomed every day, they love it,we make a game of it and I'd notice any fleas or dirt in their white bits especially.
When working for vets I trusted them implicitly but now it seems to be more about making money than anything else and that worries me a lot.
I can only advise anyone to ask their vet 'Is this really necessary?'

Aug 09, 2010 keenpetite
by: Michael

Thanks for the comment keenpetite. Although I can feel the anguish. God, I know that these droppers are potentially dangerous but your story has made me anxious about using the stuff.

I actually prefer simple manual combing using a fine flea comb regularly. That I think is the best way but it does take a bit of time and in the modern world time is short.

Aug 08, 2010 Prevention worth a pound of cure
by: keenpetite

Several years ago we lost our loving blue calico, she had fleas so husband used a common flea product, few hours later she dissappeared, one of our cats found her & quickly alerted us that something was wrong with his Mommy, she was having severe seizures, salivating profusively. Rushed her to the vet and she had to be euthanized that evening due to severe brain damage. It was a learning experience but extremely painful. About five years ago while @
WM, I picked a one drop flea product, placed it on Snuggles neck & within minutes she began to have a severe reaction. Promptly I grabbed a washcloth with Dawn liquid quickly but carefuly washed her neck, according to what vet had told us to do, As I was doing this we were rushing her to the vet. Fortunately we were able to save her & she lived to be 20 yrs old.

Aug 07, 2010 Thanks; very useful
by: Tracey (England)

Many thanks Michael, absolutely invaluable information now stored to my favourites.

Aug 06, 2010 Thanks
by: Michael

Thanks Ruth for that helpful thought. It is the kind of thing that can get overlooked.

Aug 06, 2010 Very helpful
by: Ruth

Michael that is a good and very helpful article amd may even save some cats lives.
I just want to add one thing,ALWAYS check the expiry date on any treatments (such as drop on for fleas) as a few years back there was a spate of ill and dying cats because of out of date medication being sold by mistake.
It can also happen if people have the treatment in the cupboard for a while and don't realise it's gone out of date.
You can't be too careful !

Michael Broad

Hi, I'm a 71-year-old retired solicitor (attorney in the US). Before qualifying I worked in a many jobs including professional photography. I have a girlfriend, Michelle. I love nature, cats and all animals. I am concerned about their welfare.

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