Poisons in Dogs

Lauren Jones, VMD
Written by:
Published: August 26, 2022
Poisons in Dogs

What are Poisons in Dogs?

Poisons are substances that cause damage or disturb the function of the body’s tissues, organs, or processes. Depending on the poison, clinical signs may be minimal, severe, or fatal. The five most common types of poisoning in dogs are:

  • Food poisoning

  • Alcohol poisoning

  • Household products poisoning

  • Plant poisoning

  • Medication poisoning

Accidental poisoning in dogs occurs frequently, even with the most attentive pet parents. Once an ingestion is suspected or confirmed, time is critical. Prompt veterinary treatment can save a pet’s life.

Poisoning in dogs is a medical emergency. If you think your dog ate something potentially dangerous, seek immediate veterinary care or call the ASPCA Animal Poison Control Center at 888-426-4435.

Food Poisoning in Dogs

Many human foods are extremely dangerous to dogs. It is essential to know which foods to never give your dog and what to do in the event of an accidental poisoning.

Chocolate, Coffee, and Caffeine

These products contain methylxanthines, substances which can cause vomiting and diarrhea, panting, hyperactivity, cardiac issues, tremors, seizures, and death in dogs. Methylxanthines are rapidly absorbed in the gastrointestinal tract. There is no antidote for methylxanthine toxicosis, so treatment is focused on gastrointestinal decontamination and supportive care.

Garlic and Onions

Garlic and onions belong to the Allium family of vegetables, which also include chives. These cause gastrointestinal irritation and red blood cell damage, leading to anemia. Cats are more susceptible, but in large quantities dogs can also be affected. All forms can cause problems, including raw, cooked, dehydrated flakes, powder, and supplements.

Early signs of this type of toxicosis include vomiting, diarrhea, depression, and dehydration. Over the next 1-7 days, red cell damage continues and causes pale gums, increased heart rate and breathing, weakness, brown urine, and jaundice. No antidote exists, so supportive care is needed.

Grapes and Raisins

Vets do not know why grapes and raisins are toxic to dogs, but they can cause acute kidney failure, even in small amounts. There is no specific diagnostic test or antidote. Clinical signs may start within a few hours of ingestion, with vomiting as the first symptom. Dogs may also have diarrhea, weakness, and trembling. Kidney failure can develop over the next few days and is sometimes irreversible. Supportive care is the recommended treatment for this ingestion.

Macadamia Nuts

This common snack can cause weakness, depression, vomiting, tremors, and increased body temperature in dogs. Dogs are the only reported animal with this sensitivity, and scientists do not know why. Toxic doses are approximately 1 nut per 2 pounds of body weight. Signs typically peak at 8 hours after ingestion and can resolve within 48 hours. Death has not been reported in cases of this toxicosis and, like so many other toxicities, no antidote exists, and treatment is aimed at gastrointestinal decontamination.

Xylitol

Xylitol is a sweetener found in many gums and low-calorie human products like toothpaste, candy, and baked goods. Even in small quantities, xylitol causes liver failure and life-threatening low blood sugar. Signs develop within an hour and are severe. Supportive care, GI decontamination, and close monitoring of blood sugar and other parameters are crucial in successful cases. Xylitol toxicity can be fatal. Always check the ingredient list of products in your house to assess its safety around your dog.

Yeast dough

Ingested yeast rising in the stomach creates gas, which may cause bloat. In large, deep-chested dogs, this is especially dangerous as they are at risk of the stomach bloating and twisting (a condition called gastric dilatation volvulus, or GDV), which is a life-threatening emergency. Dogs can also appear drunk after eating raw bread dough, due to ethanol byproducts.

Other toxic foods

  • Citrus stems, leaves, peels, and seeds of citrus can contain high levels of citric acid and oils that cause irritation and depress the central nervous system.

  • Coconut and coconut oil can irritate the stomach and cause diarrhea.

  • Raw meat, eggs, and bones can cause infections such as salmonella and E. coli. Bones can cause intestinal perforations and choking hazards.

Alcohol Poisoning in Dogs

Pets should never have access to alcohol. It can cause vomiting, diarrhea, decreased coordination, central nervous system depression, difficulty breathing, tremors, abnormal blood acidity, coma, and death.

Alcohol is absorbed within an hour in a dog’s stomach, although food can slow this process. Dogs are more susceptible to alcohol than humans. The amount of alcohol is measured as “alcohol by volume” or ABV. For a 10-pound dog, alcohol is lethal at about:

  • 10 ounces of 6% ABV beer

  • 5 ounces of 13% ABV wine

  • 2 ounces of 40% ABV liquor

There is no specific antidote for alcohol poisoning, so treatment is focused on GI decontamination and supportive care. Certain medications  can also aid in reducing alcohol toxicosis but can only be prescribed by a veterinarian.

Household Product Poisoning

Just like with young children, pets must be protected from potentially dangerous items around the house. Anything can cause issues when ingested, but below are some of the most common poisonous household items.

Rodenticide poisoning

Rat and mouse bait is often on the floor and accessible to dogs. There are multiple types of rat poisons, so it is important to understand the risks. The most common forms are anticoagulant rodenticides, which cause uncontrolled bleeding.

If caught and treated soon enough, dogs can fully recover from anticoagulant rodenticide poisoning with supportive care and a few months of vitamin K supplementation.

Another common rat bait is bromethalin, a neurotoxic rodenticide that causes brain swelling and seizures. Unlike anticoagulant rodenticides, bromethalin does not have an antidote and treatment is difficult once a dog is showing clinical signs. Treatment is based on aggressive GI decontamination and supportive care.

Cholecalciferol, or Vitamin D3, rat poison causes a life-threatening increase in calcium levels. It can cause a building of calcium in the lungs called pulmonary mineralization, and it can also cause heart and gastrointestinal tract problems or organ failure. Treatment is prolonged and typically requires hospitalization to stabilize and stabilize calcium levels.

Metal poisoning

A handful of heavy metals can poison dogs. Zinc toxicosis can occur after ingestion of pennies minted after 1982 or zinc-containing medications. It causes anemia, vomiting, and weakness. Lead toxicosis occurs with exposure to all forms of lead, causing issues with red blood cells, the GI tract, seizures, and other organ issues.

Any heavy metal poisoning will generally require aggressive decontamination of the GI tract, which may include emergency surgery to remove the materials.

Essential Oils

Clinical signs of essential oil poisoning include GI upset, central nervous system depression, organ damage, and respiratory issues. If inhaled, aspiration pneumonia and allergic airway syndrome occur as well.

Essential oils shouldn’t be used in the same areas of the house with your dog. Treatment for this type of toxicosis is mostly supportive. Dogs are more sensitive to wintergreen oil, sweet birch oil, eucalyptus oil, clove oil, tea tree oil, and pennyroyal oil.

Essential oils are not safe alternatives to flea and tick preventatives, as they carry a high risk of toxicity. Talk to your veterinarian about safe and effective prescription medications to keep fleas and ticks at bay.

Household chemicals

All household cleaners and products can potentially cause GI upset when ingested. Some common products from around the house can cause burns, ulceration, esophageal strictures, and fever in addition to vomiting and diarrhea. Some of the more common household products that can cause issues with dogs include:

  • Bleach

  • Carpet fresheners and shampoo

  • Fabric softeners, Febreze

  • Grout - freshly laid or in the packaging

  • Toilet bowl tablets

  • Antifreeze

Treatment is generally supportive. Induction of vomiting and GI decontamination is varied based on the specific toxicity.

Plant and Flower Poisoning in Dogs

Numerous toxic plants and flowers can affect dogs. Pet parents should use caution when planting or bringing plants in the house.

All plants have the potential to cause gastrointestinal distress, including vomiting and diarrhea. Some of the more common plant poisonings and their clinical signs include:

  • Sago palm: Vomiting, bloody stool, bruises, coagulopathy, liver failure, death

  • Tulips: Vomiting, depression, diarrhea, drooling, heart issues

  • Aloe: Vomiting, lethargy, diarrhea

  • Wild, poisonous mushrooms: Vomiting, diarrhea, lethargy, seizures, organ failure, death. Mushrooms can also contain harmful bacteria, pesticides, and heavy metals in addition to their inherent dangers.

  • Tobacco: Hyperexcitability, followed by depression, vomiting, incoordination, paralysis, death

  • Azalea: Vomiting, diarrhea, weakness, heart failure

  • Foxglove: Heart arrhythmias, heart failure, vomiting, diarrhea, weakness, death

  • Oleander: Drooling, abdominal pain, diarrhea, depression, death

  • Philodendron: Oral irritation, burns, swelling, drooling

Medication Poisoning in Dogs

Some medications are inherently dangerous at any dose, while others are dose-dependent. Dogs can easily overdose on their own medication or accidentally ingest human medications.  

Human medications

Dogs may quickly snatch a dropped human medication off the floor or even counter-surf and have access to entire bottles. Any human medication or over-the counter supplement can cause problems with pets, so always contact a veterinary professional if you know of any ingestion. Human NSAIDs are one of the more common issues with pets, most likely because almost all households keep these products around.

  • Veterinarians may recommend aspirin products in dogs, especially for antiplatelet effects or other medical issues. However, aspirin can cause gastric ulcerations, perforations, and liver injury in dogs. Never give your pet a medication or supplement without talking to your doctor about the benefits and risks.

  • Ibuprofen and naproxen can cause ulcers, kidney failure, and neurological issues.

  • Adderall and pseudoephedrine can cause neurologic, muscular, and heart issues.

  • Topical creams and ointments can cause GI upset. Dogs can also absorb human hormonal preparations and exhibit a variety of clinical symptoms.

  • Antidepressant medications can cause neurological issues in dogs.

  • Cigarettes and nicotine patches cause vomiting, cardiac and blood pressure issues, and eventually nervous system issues and possible death.

  • Petroleum jelly can cause aspiration-induced respiratory issues.

  • Kaopectate and Pepto Bismol can cause gastrointestinal ulcerations.

Pet medications

Flea and tick medication poisoning occurs when pets receive high doses of preventatives. Clinical signs can vary from topical issues (itching, chewing at application spot) to gastrointestinal issues and agitation. Some types of preventatives can cause tremors, seizures, and even death. It’s important to accurately weigh your dog to ensure they are receiving the correct dose, based on size.

Medication overdose

If the medication or preventative is prescribed for that pet, accidental ingestion is typically only a problem if they get extra doses. However, if a dog has access to another pet’s medications, it is more likely to cause an issue because of a large dose, drug interactions, and unintended drug indications.

For example, a dog may accidentally ingest an appropriate dose of a medication for high blood pressure. However, if the dog doesn’t have high blood pressure (perhaps the medication was for another dog in the same household) it could drop the blood pressure to dangerous levels.

Illegal and recreational drugs

Marijuana is one of the more common toxicities of recreational drugs in dogs. Dogs typically show gastrointestinal, nervous, ophthalmic, respiratory, heart, and neurologic signs after ingestion of marijuana.

Other illegal and recreational drugs cause a variety of neurologic, gastrointestinal, and cardiac issues. Severity and prognosis vary based on the drug involved and the amount ingested.

General Treatment Principles of Poisoning in Dogs

Each poisoning has a different recommended treatment protocol, but they share similarities. In general, poisoning cases will follow these basic guidelines listed below.

For most ingested substances: Emesis, or vomiting, is the preferred first treatment. The idea is to have your pet vomit any dangerous materials from their stomach before it is absorbed. Unfortunately, it is a race against the clock. Some substances will absorb faster than others, but in general, material remains in the stomach for approximately 2 hours.

During this time, vomiting can be a potential therapy for poisoned dogs. If the ingestion occurred after this time frame, it is less effective but may be attempted for 4-6 hours after ingestion.  In general, there are two methods of inducing vomiting:

  • Hydrogen peroxide administration can potentially make dogs vomit; however, it can also cause severe irritation and ulceration of the gastrointestinal tract. Never give your dog hydrogen peroxide without the guidance of a veterinarian.
     
  • Veterinarians prefer to use safer prescription drugs, under veterinary supervision, to induce vomiting. These can be administered intravenously or absorbed through the conjunctiva. These options are safer for your pet and allow for a veterinarian to examine and treat any other abnormalities.

After vomiting, activated charcoal is a liquid that is fed to dogs with many types of poisonings to bind the toxic substances and coat the gastrointestinal tract, preventing additional uptake.

Dogs with poisoning should receive supportive therapy, based on specific needs and severity of clinical signs. Supportive care includes intravenous fluids, oxygen supplementation, pain, heart, or seizure medications as indicated, and may even require urinary catheterization for those animals unable to control their bladder.

What To Do If You Think Your Dog Was Poisoned

Identifying a potential poisoning is the first step to getting your dog healthy again. If you know what your pet ate, gather all the information you can, including wrappers and ingredient lists, to discuss with your veterinarian.

Contact your veterinarian, an emergency veterinarian, the ASPCA’s Animal Poison Control Center at 888-426-4435 or the Pet Poison Helpline at 855-764-7661. These services are staffed 24/7 by veterinarians, including toxicologists. Follow-up calls for the same incident are usually included in the consultations.

Many pets will accidentally ingest a potentially dangerous nonfood item throughout their life. Early veterinary intervention is crucial in all cases of potential poisonings. The sooner your dog receives immediate care, the better the outcome for all. 

References

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  10. Gwaltney-Brant S, Dekker M, Brister J. Veterinary Information Network® Bromethalin Toxicosis (Canine). October 2021.

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Featured Image: iStock.com/Vadim Gavrilov


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