Laurie Anne Walden, DVM
Prescription and over-the-counter human medications are the most common toxins that pets ingest, according to the ASPCA Poison Control Center. This article covers some of the over-the-counter products that are hazardous to pets.
Pets can be exposed to these products either accidentally or intentionally. Keep all medications and supplements out of your pets’ reach, and never assume that a product that is safe for people is also safe for pets. Dogs and cats process drugs differently from humans. A dose of medication that is OK for a 50-lb child could be very dangerous for a 50-lb dog.
Ibuprofen, naproxen, and aspirin are nonsteroidal anti-inflammatory drugs (NSAIDs). Some brand names are Advil, Motrin, and Aleve. In dogs and cats, these drugs can cause digestive tract ulcers, leading to diarrhea, belly pain, and bleeding. NSAIDs can also cause liver and kidney failure at higher doses. Although low doses of aspirin can be used with proper precautions in dogs, ibuprofen and naproxen are not safe for pets. NSAIDs and other pain relievers that are formulated especially for dogs and cats are safer and more effective.
Acetaminophen (brand names Tylenol and Excedrin) is highly toxic to cats even in small amounts. It damages cats’ red blood cells and can cause liver failure and death. Dogs are less sensitive than cats to the toxic effects but can also sustain liver damage from acetaminophen.
Cold and cough remedies
Decongestants like pseudoephedrine (in Sudafed) and phenylephrine (in many oral decongestants and nasal sprays) can cause agitation, hyperactivity, heart rhythm abnormalities, seizures, and death in pets. Some antihistamine products, especially combination or multisymptom products, include decongestants. Always check the active ingredient list before giving any antihistamine to your pet.
Other ingredients in decongestant nasal sprays—like oxymetazoline, the active ingredient of Afrin—can cause weakness, collapse, hyperactivity, vomiting, and heart rhythm abnormalities in pets. Pets are usually exposed to this type of product by chewing the bottle.
Although the cough suppressant dextromethorphan (in Robitussin and Delsym) can be used in dogs, high doses cause nervous system problems. As with antihistamines, always check the ingredient lists of cough remedies; many include ingredients that are not safe for pets.
Tetrahydrozoline, the active ingredient of Visine, is in the same drug class as oxymetazoline and causes similar symptoms in pets.
Vitamins and iron supplements
Flavored chewable vitamins may be attractive to dogs. High doses of vitamin D can cause kidney failure. Very high doses of vitamin A can also cause serious problems in pets. Iron toxicosis can cause digestive tract ulcers, bleeding, liver damage, and seizures.
Chewable vitamins may also contain xylitol, an artificial sweetener. Dogs that ingest xylitol can develop low blood sugar levels and liver failure.
Zinc oxide, an ingredient in some sunscreens and other skin creams, causes vomiting and diarrhea if swallowed.
Herbal supplements and essential oils
The dietary supplement 5-hydroxytryptophan (5-HTP; Griffonia seed extract) can have serious effects on the digestive system, nervous system, heart, and lungs in dogs and cats. Vomiting, diarrhea, seizures, and death can result.
Herbal supplements marketed for weight loss and energy may include guarana, which contains caffeine, and ma huang, a source of ephedrine. Dogs that accidentally ingest these products can develop hyperactivity, seizures, and heart rhythm abnormalities. Death is possible at high doses.
Peppermint oil is toxic to cats, potentially causing digestive tract, nervous system, and liver problems. Tea tree oil, even small amounts applied to the skin, can be toxic to dogs and cats (cats are more susceptible than dogs). Exposure can cause tremors, coma, and liver damage.
Nicotine in cigarettes, e-cigarette cartridges, nicotine patches, and nicotine gum is toxic to pets that ingest these products. Nicotine toxicosis can cause vomiting, seizures, and death.
For more information about pet poisonings
ASPCA Animal Poison Control
Pet Poison Helpline
Khan SA. Toxicities from over-the-counter drugs. Merck Veterinary Manual website. Accessed November 26, 2017.
Patel T, Brutlag A. Drug store toxins in small animals. In: Plumb DC, ed. Plumb’s Veterinary Drug Handbook, 8th ed. Ames, IA: Wiley-Blackwell; 2015:1683-1687.
Poisonous household products. ASPCA Animal Poison Control website. Accessed November 26, 2017.
Top 10 human medications poisonous to pets. Pet Poison Helpline website. Accessed November 26, 2017.
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Laurie Anne Walden, DVM
The Halloween safety post touched on treats that can be hazardous to pets. Here’s a more detailed list of common foods that are dangerous for dogs and cats.
Alcohol, raw bread dough, and raw pizza dough
These foods contain ethanol, a type of alcohol. Pets are most often exposed by accidentally consuming alcoholic beverages. Toxicosis has also been reported in dogs who ate raw yeast dough or rotten apples. Ethanol consumption can cause vomiting, dehydration, sedation, coordination problems, low body temperature, difficulty breathing, coma, and death.
Uncooked bread or pizza dough can also cause life-threatening bloat. Yeast continues to rise in the stomach, filling the stomach with a large mass of dough in addition to the gas given off by fermentation.
Chocolate, coffee, and other caffeine-containing products
The toxic ingredients of chocolate are caffeine and theobromine, which are both in a class of compounds called methylxanthines. Other products that contain methylxanthines (coffee, black tea, soft drinks, mulch made of cocoa bean shells, some herbal supplements, and some human medicines) are also dangerous to animals. Low doses of methylxanthines cause vomiting, diarrhea, restlessness, and increased thirst. High doses cause heart rhythm problems, seizures, coma, and death. Chocolate consumption is the most common cause of methylxanthine toxicosis in dogs. In general, the darker and more bitter the chocolate, the higher the methylxanthine content and the higher the risk.
Grapes, raisins, currants, and sultanas
Grapes, either fresh or dried, can cause life-threatening kidney failure in dogs. Although some dogs can eat grapes and raisins without showing any symptoms, others develop kidney failure after eating only a few. Because we do not yet know why some dogs are sensitive, it’s best to avoid giving dogs any grapes or their dried versions, including raisins in baked goods. In susceptible dogs, grape consumption causes vomiting, diarrhea, loss of appetite, and belly pain. Dogs can develop kidney failure and die within 3 days of eating grapes or raisins.
Home beer brewing can expose pets to hops, which are used in the brewing process. In dogs, both fresh and spent hops cause a dangerous increase in body temperature called malignant hyperthermia. Signs include anxiety, increased heart rate, vomiting, panting, elevated body temperature, seizures, and death.
Dogs who eat macadamia nuts may develop vomiting, weakness, loss of coordination, lameness, tremors, and high body temperature. No deaths have been reported.
Onions, garlic, leeks, and chives
These vegetables and other members of the Allium genus contain compounds that irritate dogs’ and cats’ digestive tracts and damage their red blood cells. Cats are especially sensitive to the toxic effects. Consumption can cause vomiting, diarrhea, belly pain, loss of appetite, anemia, and jaundice. Be sure to check the ingredient lists of any human foods you give your pets. Some varieties of chicken baby food, for example, contain onion or garlic for flavor.
Xylitol is an artificial sweetener used in sugarless gum, sugar-free candy, breads, other baked goods, and some human dental products. Drinking water additives for pet dental care may also contain xylitol. Although xylitol is safe for most species, in dogs it interferes with insulin metabolism and can cause a life-threatening drop in blood sugar levels. Dogs that consume xylitol can also develop liver failure. The first symptom of toxicosis is usually vomiting. Other signs include weakness, loss of coordination, seizures, jaundice, and coma.
Food ingredients that aren’t good for people aren’t good for pets either. These include bones (choking, perforation of the digestive tract), moldy food (mycotoxins), raw meat or eggs (bacterial contamination), and rotten fruit (ethanol). High-fat food or indiscriminate eating can also cause inflammation of the pancreas in dogs.
Cortinovis C, Caloni F. Household food items toxic to dogs and cats. Front Vet Sci. 2016;3:26.
Food hazards. Merck Veterinary Manual website. Accessed November 10, 2017.
People foods to avoid feeding your pets. ASPCA Animal Poison Control website. Accessed November 10, 2017.
Photo by Rohit Tandon
Laurie Anne Walden, DVM