How Toxic Is Borax to Cats?

We’ve all heard of the many uses for borax, one being a flea treatment for cats.

But have you ever wondered if it is safe for cats? Dr. Angela Damant, D.V.M says less than 5 grams (the weight of a single credit card) of Borax is enough to kill a cat. 

So how exactly can you protect your cat from borax? And what should you do if your cat accidentally ingests some of it?

Keep reading on to find out!

What is borax?

Borax, also known as sodium borate, is a chemical made of boron, sodium, and hydrogen. This white powdery substance is a commonly used household product. Many cleaning solutions contain borax. Borax also doubles as an insecticide/pesticide for keeping ants and mice at bay.

The chemical appears in laundry detergents for removing tough stains. Borax is also a water treatment because it is alkaline and helps neutralize the pH in acidic water.

How is borax toxic to cats?

Some people recommend Borax as a DIY solution for flea-infested cats. The instructions usually involve sprinkling Borax around the house, on the cat’s body, and even in their food tray or litterbox.

But what most owners don’t know is that just 5 grams of Borax, if ingested by your cat, can be lethal. And because cats are such fastidious groomers, there is a high likelihood that this could happen.

Borax ingestion can result in:

1. Respiratory distress

Borax is a mild lung and throat irritant. But inhaled in large quantities, it can also result in respiratory distress. When this happens, your cat will become oxygen-deficient and start panting.

Their gums might turn blue, and some cats will foam at the mouth. Borax inhalation is an emergency and can turn fatal if not immediately treated by a veterinarian. If your cat shows even the slightest respiratory distress after coming in contact with borax, contact a veterinarian immediately.

2. Kidney damage

Borax is metabolized by the kidneys after ingestion; a large enough quantity can cause kidney damage or even complete renal failure.

See also  Do Bengal Cats Smell? Why Do Bengal Cats Smell?

Exposure to small amounts of borax can add up to kidney damage over time. Look for symptoms of weakness, weight loss, excessive thirst, and bloody stools; all signs that your cat’s kidneys are in crisis.

3. Reproductive organ damage

Borax can be detrimental to your cat’s reproductive organs. After coming in contact with their genitals, the chemical can cause irritation and skin problems. Not only that, but it can also lead to the deterioration of the reproductive system

 reducing the chances of your cat becoming pregnant. Exposing pregnant cats to borax can sometimes result in a miscarriage.

4. Developmental failure

Using borax to treat fleas in kittens is the last thing you’d want as it can lead to development issues. The chemical can inhibit their growth rate and prevent their body from reaching full size. Your cat might also suffer from mobility issues in the future if you have used borax regularly since kittenhood.

5. Poisoning

In the worst-case scenario, over-consumption of borax will lead to the death of your cat. While not common because cats are rarely exposed to so high a dosage, it is not unheard of.

If you suspect your cat ingested a large amount of borax, getting them to a vet right away can increase their chances of survival.

Look for the following symptoms to identify borax poisoning in your cat:

  • Diarrhea
  • Stomach ache
  • Excessive thirst
  • Respiratory difficulties
  • Scratch marks on skin
  • Altered conscious/mental state

How to avoid borax poisoning?

The easiest way to prevent poisoning is to remove borax from your house entirely. And if you do use it, keep it in a sealed container where your cat cannot reach it.

See also  Why Cats Love Looking Out Windows

You should also secure household products that contain borax as an ingredient. Toilet bowl cleaner, laundry detergent, glass cleaner, and even kid’s slime are on this list. Put all such products away in a closed cabinet or shelf your cat cannot reach.

It’s also possible for your cat to lick borax cleaners off the floor or tiles. So whenever you use such solutions, remember to rinse them off thoroughly to remove any residual borax. If you’re using laundry boosters, give the machine a couple of cycles with plain water.


What are other household chemicals toxic to cats?

Many chemicals that we use daily are toxic to cats. Some of these include:

  • Anti-freeze
  • Bleach
  • Insecticides/Pesticides
  • Detergents
  • Fertilizers

Certain foods should be kept away from your cat because they are highly toxic for felines. The list includes garlic, onion, chocolate, caffeine, sodas, grapes, and raisins. Human medications like anti-depressants, vitamins, and supplements can also cause an overdose in cats.

What would happen if your cat ate borax?

It depends on how much borax your cat has ingested. Small doses are usually harmless and may cause mild stomach upset at best. A mild dose can cause a slight respiratory depression or skin inflammation. But a one-time high dose could result in poisoning. 

How to treat a cat for borax poisoning?

To treat borax poisoning, immediately contact your vet and rush them to the nearest clinic. If your cat is experiencing severe symptoms, your vet might ask you to induce vomiting. At the clinic, your vet will give IV access to dilute the borax and prevent renal failure. 

Is baking soda dangerous for cats?

Yes, baking soda is toxic to cats in large quantities. Slightly less than two tablespoons of pure baking soda can poison most cats. It will result in many of the same symptoms as borax poisoning, like diarrhea, tremors, seizures, disorientation, and shortness of breath.

Photo of author

Susan Dorling

I am a pet expert with years of experience working with a variety of animals. From dogs and cats to birds and exotics, I have a deep understanding of their unique needs and behaviors. I am dedicated to helping pet owners provide the best care for their furry friend.

Leave a Comment