Boric Acid Poisoning in Dogs

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Boric Acid Poisoning in Dogs
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Boric acid is a naturally occurring compound made up of boron, oxygen, and hydrogen in the chemical formula H3BO3. The Chemical Co. describes boric acid crystals as looking like fine-grained table salt in the crystal form or like baby powder in the powdered form. It is white, odorless, and nearly tasteless. Many people use boric acid as a natural form of pest control in the home because it can be effective, and it's not based on synthetic chemicals like other pest controls are.

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Although boric acid can be an effective pest control, boric acid and pets don't mix. When they find boric acid, dogs can be curious enough to eat it. The Cooperative Extension says that boric acid poisoning in dogs results in digestive issues, disorders, seizures, skin redness, and other mild to serious problems.

Understanding boric acid uses

Boric acid is a combination of water and boron, which becomes a powder. Boron and boric acid occur naturally in the environment in soil, water, and plants. Boric acid was first registered as a pesticide by the Environmental Protection Agency in 1948. Boric acid is often used as cockroach bait or ant bait. In this form, it is mixed with chemical sweeteners that make it attractive to insects, and dogs seem to like it too.


When used against cockroaches, boric acid is often applied as a dust or powder. Roaches crawl over the dust and it adheres to their body, which they then eat as they clean themselves. If insects eat boric acid, it disrupts their stomach. Since its structure is crystalline, it can also scratch the outside bodies of insects. It can kill insects and plants by drying them out. The problem with boric acid and pets is that the boric acid is often mixed with a food bait that can make it attractive to insects as well as dogs.

Borax poisoning

Borax is a sodium salt of boric acid. Boric acid and borax are chemically similar and similar in appearance. Both are a white or colorless crystalline powder. There are some safe uses, such as using boric acid to treat infections in your dog's eyes. However, Victoria, British Columbia's state agriculture program lists boric acid as a common poison for dogs.


When exposed to powdered boric acid or borax, dogs will sometimes lick it, and ingesting too much of it can be toxic. The Cooperative Extension says that borax is harmful to pets in large doses. The size of the dose that would be considered harmful varies with the size of the dog.

Signs of toxicity

Symptoms of boric acid or borax poisoning usually first appear within two hours. Some of the first signs of consuming boric acid are excessive salivation, thirst, fever, vomiting, retching, depression, loss of appetite, diarrhea, and abdominal pain. The vomit may have a blue-green color, as might the stool.


When exposed to a large amount of boric acid or borate salts like borax, dogs could show signs of seizures and might develop reddish-violet colored skin. If your dog gets boric acid on his skin, it could look red and inflamed. The Cooperative Extension says that older animals or young animals may be more sensitive to boric acid and borate salts than adult animals.

Reducing the possibility of exposure

You can reduce or eliminate your pet's risk of exposure to boric acid by using it in a responsible manner. If the usage is limited to areas that the pet cannot access, then there is less chance that your dog will encounter it. Arrow Termite & Pest Control says to apply it where cockroaches and other insects will walk through it. This is often under sinks or behind refrigerators. Cockroaches will avoid it if they see too much of the powder, so you want to apply just enough to stick to them.


If you're using a food attractant such as sugar to make the boric acid attractive to ants, don't put it where your dog could lick it. Under the refrigerator, under the bathroom sink, or in the upper food cupboards are places where ants can find it but your dog can't get to it.

If you are working with boric acid as a powder, be careful as you apply it and avoid breathing it in while you work. If you accidentally overapply it, don't vacuum it. This may result in the powder becoming airborne and landing where you don't want it to.

Research shows that boric acid is an effective form of pest control when used responsibly. While it could be harmful if your pet does ingest it, using it responsibly drastically reduces these concerns.

Always check with your veterinarian before changing your pet’s diet, medication, or physical activity routines. This information is not a substitute for a vet’s opinion.