Activated Charcoal for Dogs and Cats

Veronica Higgs, DVM
By Veronica Higgs, DVM on Mar. 1, 2023
veterinarian examining a dachshund

If you’ve taken your pet to the veterinarian for ingestion of a toxin, chances are they returned home with black liquid residue around their mouth or even on their paws. This is activated charcoal, a common material used to absorb toxins from pets’ bodies. But while this treatment can be lifesaving, precautions are necessary.

What Is Activated Charcoal?

Activated charcoal has often been called “the universal antidote” for absorbing toxins from the gastrointestinal tract. This, in turn, reduces or even prevents systemic (body-wide) toxin absorption. 

Activated charcoal is made by burning wood at extremely high temperatures, then using chemicals to activate the charcoal particles. This allows the charcoal to bind bodily toxins. Activated charcoal may be used alone or with a cathartic (a medication that acts similarly to a laxative) to increase the speed at which the charcoal-bound toxin moves through the gastrointestinal tract and thus decrease the chances of reabsorption.

What Is Activated Charcoal Used for in Pets?

Activated charcoal is used primarily in acute poisoning cases in dogs and cats. Activated charcoal will absorb most toxins pets ingest; the charcoal, when given orally, decreases the toxic effects of the poisoning.

Common poisonings that may be improved by activated charcoal administration include:

However, some toxins can’t be bound by activated charcoal, rendering the treatment ineffective. This includes:

If your pet has ingested a toxin, take them to your veterinarian or a veterinary emergency hospital immediately. Time is always a factor in toxicity cases, and the sooner the vet can examine your pet, the better the chances of a successful outcome. If you cannot reach your veterinarian, call the Pet Poison Helpline at 855-764-7661 or the ASPCA Animal Poison Control Center at 888-426-4435 for help determining if your pet needs to go to the emergency room. 

If your dog or cat ingested a toxin within the past two hours and is not showing clinical signs of poisoning, your veterinarian will likely start by inducing vomiting at the hospital to remove as much of the undigested toxin from their system as possible. Depending on the toxin, the vet may also give your pet activated charcoal to decrease the absorption of any remaining poison in the digestive tract. Activated charcoal is most effective when given within the first hour after ingesting a toxin, but it can be given up to four hours after ingestion. 

How To Give Your Pet Activated Charcoal

Activated charcoal should only be given by your veterinarian. If your pet inhales activated charcoal, this can be life-threatening. In some cases, a nasogastric tube (a tube placed in the nose that goes into the stomach) may be used for administration. 

It’s very important for a vet to perform a physical examination before giving your dog or cat activated charcoal, as there are several contraindications, or risk factors, that can make the treatment life-threatening. Reasons a veterinarian may consider it unsafe to give activated charcoal to your pet include:

  • Neurologic signs such as disorientation, tremors, or seizures, as well as decreased gag reflex: Altered mental status decreases the pet’s ability to protect their airway, and increases the risk of aspiration (breathing medication or vomit into their lungs) in dogs and cats.

  • Dehydration: Activated charcoal pulls fluid from the body into the gastrointestinal tract, which can worsen dehydration.

  • Elevated sodium levels (hypernatremia): When activated charcoal pulls fluid from the body into the gastrointestinal tract, this also causes the blood sodium level to increase in dogs and cats. Hypernatremia can cause life-threatening neurological issues, such as swelling in the brain and seizures.

  • A compromised gastrointestinal tract: Whether it’s a recent gastrointestinal surgery or suspected intestinal blockage, this makes activated charcoal inadvisable. If the intestines are not moving properly, constipation can occur. Constipation may be worsened by activated charcoal or cause toxins absorbed by activated charcoal to reabsorb into the body. And if the bowels are not intact, activated charcoal could leak into the abdomen.

  • Concurrent diseases such as acute kidney failure (in dogs and cats), diabetic ketoacidosis (in dogs and cats), and megaesophagus (in dogs and cats) may also hinder activated charcoal administration. 

Sometimes activated charcoal will be given repeatedly to absorb and eliminate as much of the toxin as possible. That said, if the charcoal is administered with a cathartic, that combination will only be given once. Additional doses will be plain activated charcoal; repeated doses with a cathartic can worsen secondary dehydration and hypernatremia. 

Activated charcoal is most effective when given as a slurry, usually with water or canned food. Administration of a small amount of food with activated charcoal may increase its palatability and help with ease of administration, particularly to dogs. Activated charcoal tablets and capsules are not considered very effective and are not used in veterinary medicine. 

How Much Activated Charcoal Can Your Dog or Cat Have?

The activated charcoal dosage depends on the toxin ingested, size of your pet, and the activated product used. Your veterinarian may consult the activated charcoal label or manufacturer, veterinary drug resource, or a pet poison control center for guidance and dosing information for activated charcoal in dogs and cats.

Side Effects of Activated Charcoal

Activated charcoal is generally well tolerated, but the main side effect or complication is vomiting after administration with risk of aspiration. Other possible side effects include:

  • Dehydration

  • Electrolyte abnormalities

  • Constipation

  • Diarrhea (if a cathartic was used)

If your pet is on daily medication, ask your veterinarian if you need to adjust the dosing. In most cases, activated charcoal will also absorb oral medications. Often, your pet’s medications will need to be given at least two to four hours after they receive the charcoal or be temporarily switched to intravenous (IV) administration. 

Activated charcoal will stain clothing or fur, and it’ll also color your pet’s stool jet-black for 24–48 hours after administration. This is normal, but if it persists, please inform your veterinarian. Persistent black stool can be a sign of gastric ulceration or stomach bleed in dogs and cats. 

Featured Image: iStock/SeventyFour

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  1. Wilson HE, Humm KR. In vitro study of the effect of dog food on the adsorptive capacity of activated charcoal. J Vet Emerg Crit Care (San Antonio).
  2. Peterson, Michael E. Small Animal Toxicology. 3rd ed. Elsevier Saunders; 2001.


Veronica Higgs, DVM


Veronica Higgs, DVM


Dr. Veronica Higgs is a 2010 graduate from Auburn University College of Veterinary Medicine.  She then completed a 1-year rotating...

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