pet poison

Protect Your Pets: Three Common Human Products That Can be Poisonous to Your Paw Pals

As pet owners, we know that some human foods and products are dangerous to our furry family members. But have you ever wondered why they are dangerous? How and how much? And what will happen if they do consume those products? In this article, we will delve into three household products that can have a dangerous effect on pets while us humans can handle them without a problem.

What else is different about humans and our pets?

I say, “what else”, because it is fairly obvious us bipedal human beings are very different from our quadrupedal dogs and cats. However, there are a lot more differences to think about once we consider our organ systems and metabolism. Dogs and cats have drastically different metabolisms and physiologies compared to humans. For example, the livers between humans, dogs, and cats operate quite differently. Livers all have the same general purpose: to break-down molecules, metabolize them into other molecules, and generally clean out the blood of toxins and drugs.[1] The metabolism of most drugs and molecules come from a family of enzymes called Cytochrome P450. There are thousands of enzymes under this family, however only about 50 of these enzymes do most of the work in our livers.[2] These enzymes are distributed differently depending on whether you are a human, dog, or cat. This difference in distribution is what causes differences in metabolisms. The presence and absence of specific enzymes can determine what humans, dogs, and cats can break-down.[3] Without efficient metabolism of certain compounds, our pets may become sick and poisoned if they consume these products.

Sickly Sweet Chocolate

Chocolate contains compounds called theobromine and caffeine. These molecules fall under a family of chemicals called methylxanthines; they act upon receptors within the nervous system to stimulate our bodies. This is why caffeine makes us feel more awake and alert. The difference in caffeine and theobromine for humans, dogs, and cats is how long it lasts within each body. Theobromine sticks around a pet’s body significantly longer compared to a human (4.5 days vs 2.5 days).[4] Because of this slow rate of metabolism, this toxic compound can easily accumulate within the pets’ liver can create poisonous effects. These effects may even become amplified and even life-threatening depending on…

    • The weight of the pet
      • Smaller bodies means smaller doses needed to reach adverse effects
    • The “darkness” of the chocolate
      • Darker chocolates have more theobromine[4]
    • The amount of chocolate eaten

Cats are equally affected by chocolate compared to dogs, but the incidence of chocolate poisoning in cats is much more rare. Cats cannot taste sweetness, are usually not prone to eating unknown foods, and do not inhale their food like dogs.[5]

If you witness your pet eating chocolate, they may be okay depending on the above factors like their weight. When in doubt, call the Animal Poison Control Center (855-764-7661). They may charge a consultation fee, however it will be cheaper than a hospital visit for potentially mild poisoning or no poisoning at all. Take your pet to the ED as soon as possible if you see the following signs[5]:

    • Vomiting and diarrhea
    • Unusual hyperactivity
    • Excessive thirst and urination
    • Muscle stiffness and seizures

Be careful where you store your chocolate in the house. The risk increases during some holidays like Halloween and Easter where chocolate is more abundant. And of course, do not voluntarily feed your pets chocolate!

An Eye-opener on Alcohol

It may be humorous to give your pet some alcohol while drinking your own, but there is nothing humorous about the poisonous effects your pet may receive! Alcohol is rapidly absorbed in the pet’s stomach and distributed throughout the body. Alcohol is even absorbed fairly well through their skin, so some pets may have alcohol poisoning after spraying them down with alcohol-based flea spray.[6] Ingestion of alcohol does not only come from beer and spirits but also from household cleaners that were not stored carefully.

When alcohol is consumed, the effects are quite similar between pets and humans. It depresses their nervous system and cardiovascular system, makes them dehydrated, and may lead to vomiting.[6,7] Unlike humans, dogs’ and cats’ livers are not equipped with the enzymes capable of breaking down alcohol. Effects that we may see with humans happen with less alcohol and faster with pets. Like chocolate, some factors may determine how severe the alcohol poisoning can be[7]:

    • Weight of the pet
    • Proof of the alcohol
      • Higher proof = less alcohol needed to reach toxicity
    • Amount consumed
    • Type of alcohol consumed (ethanol vs methanol vs isopropyl alcohol)
      • Isopropyl alcohol is the worst for pets and will result in toxicity even at very small amounts
      • Isopropyl alcohol is commonly found in alcohol-based flea sprays
    • How long ago did the pet eat something
      • Empty stomachs causes faster absorption leading to faster effects

If you witness your pet consuming from household cleaners or spirits, call the Animal Poison Control Center (855-764-7661). Alcohol could potentially be more serious than chocolate at lower doses,[7] so it is worth having the veterinarians perform the calculations and consult you through what to do. Take your pet to the ED as soon as possible if you see the following signs[7]:

    • Vomiting and hypersalivation
    • Staggering and collapsing
    • Hyperexcitation or depression
    • Excessive urination and incontinence
    • Tremors and seizures

Store your household cleaners carefully and responsibly so your pets cannot get to them. Check ingredients on skin products to make sure they do not contain alcohol. Do not voluntarily give your pets alcohol! You having a good time with alcohol does not mean your pets will have the same good time.

No Pain Relief from Tylenol

            Tylenol (acetaminophen) is a common over-the-counter medication for pain and fever relief. Just because your pets can have pain does not mean Tylenol is safe for them to take! Normally in humans, we have an enzyme that can metabolize acetaminophen into a safe, inactive form to be urinated out of our systems. Dogs and cats have less of that enzyme compared to humans which allows acetaminophen to be metabolized into a toxic compound that can lead to extensive liver damage.[8] Cats are especially susceptible since they are more deficient in this enzyme than even dogs, requiring lower doses to achieve poisonous effects.[9]

As mentioned before, the toxic metabolite of Tylenol in pets can cause liver damage. It can also cause their red blood cells to stop carrying oxygen throughout the body and kidney damage.[9] Factors that determine severity include:

    • Weight of the pet
    • How much Tylenol consumed
    • Cat or dog
      • Cats are much more sensitive than dogs… only half a tablet of Tylenol can lead to a cat’s death!

If you witness your dog consuming Tylenol, call the Animal Poison Control Center (855-764-7661). Toxicity in dogs is not that common as it usually takes about four times as much Tylenol to achieve toxicity compared to cats.[8] When in doubt, it is still worth calling the Poison Control Center for consultation and next steps. If you see your cat take Tylenol, you should immediately take them to the ED. Take your pet to the ED as soon as possible if you see the following signs[9]:

    • Lips are turning blue or gray (cyanosis)
    • Vomiting
    • Swelling of the paws, legs, and face
    • Chocolate-colored urine
    • Hyperventilation

Be sure to carefully store Tylenol and make use of the child-proof cap. Do not voluntarily give Tylenol to your pets if they are in pain or sick. Consult a veterinarian first before giving any medication to your pets.


There are many different products that can be harmful for your pets, but these three featured items are some of the most common within the household and the ones with the most questions. Most poisonings can be prevented with proper storage, comprehensive research, and professional consultations. Remain diligent to protect your furry family members from unsafe products!


By: Max Staskauskas Pharm. D. Candidate

Edited by: Jimmy Stevens, Pharm. D.



  1. Liver: Anatomy and Function. John Hopkins Medicine. 2023. Accessed April 25th, 2023.
  2. Lynch T, Price A. The effect of cytochrome P450 metabolism on drug response, interactions, and adverse effects. Am Fam Physician. 2007;76(3):391-396.
  3. M.N. Martinez, J.P. Mochel, D. Pade. Considerations in the Extrapolation Drug Toxicity Between Humans and Dogs. Current Opinion in Toxicology. S2468-2020(20)30039-5.
  4. Gwaltney-Brant SM. Chocolate Toxicosis in Animals. In: Merck Manual Veterinary Manual. Merck & Co., Inc; 2021. Updated November 2022. Accessed April 25, 2023.
  5. Tilley LP., Smith FWK Jr., Sleeper MM., Brainard BM. Chocolate Toxicosis. In: Blackwell’s Five-Minute Veterinary Consult: Canine and Feline. 7th ed. Wiley Blackwell; 240-241. Accessed April 25, 2023.
  6. Gwaltney-Brant SM. Alcohols. In: Merck Manual Veterinary Manual. Merck & Co., Inc; 2013. Updated November 2022. Accessed April 25, 2023.
  7. Tilley LP., Smith FWK Jr., Sleeper MM., Brainard BM. Ethanol Toxicosis. In: Blackwell’s Five-Minute Veterinary Consult: Canine and Feline. 7th ed. Wiley Blackwell; 473. Accessed April 25, 2023.
  8. Khan SA. Analgesics (Toxicity). In: Merck Manual Veterinary Manual. Merck & Co., Inc; 2014. Updated November 2022. Accessed April 25, 2023.
  9. Tilley LP., Smith FWK Jr., Sleeper MM., Brainard BM. Acetaminophen (APAP) Toxicosis. In: Blackwell’s Five-Minute Veterinary Consult: Canine and Feline. 7th ed. Wiley Blackwell; 10-11. Accessed April 25, 2023.