FrançaisCan dogs have coffee?
No. Coffee contains caffeine, which can cause restlessness, vomiting, a fast or irregular heartbeat, tremors, high body temperature and seizures in dogs [5, 9]. One or two licks of coffee are unlikely to poison most dogs, but unused grounds, beans, tea bags and caffeine supplements can cause serious poisoning [8].
If your dog has eaten coffee grounds, beans, pods, pills or an energy drink, call your vet or a pet poison line now, even if your dog seems fine. Keep the package: the product and the amount guide the vet.
Why caffeine is dangerous for dogs
Caffeine is a methylxanthine, like theobromine in chocolate. It blocks adenosine receptors, which normally calm the nervous system. The result is a stimulated brain, a faster and stronger heartbeat and more urine [1, 5].
Caffeine is absorbed fast: 99% within 45 minutes, with a peak in the blood after 30 to 60 minutes [4]. Its half-life in adult dogs is about 4.5 to 6.7 hours [1, 5], and it can be longer after a large dose, because the body clears high amounts more slowly [5]. Dogs and cats appear to be more sensitive to caffeine than people [8].
The bitter taste does not stop dogs from eating it [4]. Large coffee drinks with sweeteners and cream may even attract them, and they can hold extra shots of espresso [8].
Coffee grounds, beans, pods, tea, energy drinks and pills
Caffeine is found in coffee, tea, soft drinks, energy drinks and guarana, and in caffeine tablets sold as stimulants [6, 8]. Poisoning in dogs is most common with concentrated sources: stimulant pills, diet products, coffee beans, caffeinated drinks and chocolate [5].
- Coffee grounds and beans: unused grounds or beans can cause serious poisoning [8]. Pods and capsules hold ground coffee, so treat a chewed pod the same way.
- Brewed coffee: a 12-ounce cup of regular brewed coffee holds about 113 to 247 mg of caffeine [10].
- Tea and tea bags: black tea holds about 71 mg and green tea about 37 mg per 12 ounces [10]. Tea bags can be dangerous [8], and tea also contains theophylline, another methylxanthine [4].
- Energy drinks and soda: 41 to 246 mg per 12 ounces for energy drinks, 23 to 83 mg for caffeinated soft drinks [10]. Energy shots and pouches also count [8].
- Caffeine pills and supplements: tablets can contain up to 200 mg each [5], and caffeine tablets are a common cause of methylxanthine poisoning in dogs [7]; pre-workout and weight-loss supplements may also contain caffeine [8].
- Guarana: a natural caffeine source found in diet and energy products. Its effect can last longer than other forms of caffeine [2].
- Chocolate: contains caffeine as well as theobromine [1]; see chocolate and dogs.
Mild signs such as nausea have been reported from 7 to 10 mg/kg of caffeine, and a median lethal dose of about 140 mg/kg is cited, but severe signs and death can occur at much lower doses and dogs vary [1, 4, 5]. Call your vet or a pet poison line whatever the amount. Decaffeinated coffee still holds some caffeine: 2 to 15 mg per 8-ounce cup [10].
Signs, timing and how long it lasts
Signs of caffeine overdose can appear within 2 hours [4]; a review gives 2 to 4 hours for the first signs of methylxanthine poisoning [6]. With guarana supplements, signs start between 30 minutes and 8 hours and last 24 to 72 hours [2]. In severe cases, signs can persist up to 72 hours [1, 4].
- First signs: restlessness, thirst, vomiting, diarrhea, panting and more urine, sometimes urine leaking [6, 9].
- Nervous system: hyperactivity, wide pupils, wobbling, stiffness, tremors and seizures [2, 5, 6].
- Heart and body: a fast heart rate, abnormal rhythms, high blood pressure and high body temperature [2, 5].
- Severe cases: muscle breakdown (rhabdomyolysis), coma and death [5, 6].
- In real cases: of 47 dogs that ate a supplement with guarana and ephedrine (ma huang), 80% showed signs within 8 hours and signs lasted up to 48 hours. Hyperactivity, tremors, seizures or behavior changes were seen in 83%, vomiting in 47%, a fast heart rate in 30% and high temperature in 28% [3].
Death, when it happens, is usually due to heart rhythm problems, overheating or breathing failure [1].
What the vet checks, and why
There is no quick clinic test for caffeine. The diagnosis rests on what the dog ate and the signs, and the vet rules out other stimulants such as amphetamines or decongestants [1]. Specialist laboratories can find caffeine in blood or stomach contents, but those results come later [4, 5]. Routine blood work can even be normal early on [4].
- Abbreviation K or potassium, in the electrolyte block with sodium (Na) and chloride (Cl).
- Result 3.6 mmol/L in this illustrative line: below the interval. In a reported caffeine case, potassium was 3.84 on arrival and 3.72 the next day, under that laboratory’s interval [5].
- Unit mmol/L or mEq/L: for potassium the two numbers are the same.
- Laboratory interval The example uses the dog interval of the Merck Veterinary Manual [14]; each laboratory sets its own.
- Flag L: below the interval. In methylxanthine poisoning, low potassium can appear late and make heart rhythm problems worse, so the vet may recheck it [1].
| Check | What can be found | Why it matters |
|---|---|---|
| Heart rate and ECG | Fast heart rate, extra beats from the ventricles | Heart rhythm problems are a main danger [1, 5] |
| Blood pressure | Often high | Caffeine pushes the heart and vessels [2, 4] |
| Temperature | High | Overheating is common and can be fatal [1, 4] |
| Potassium | Low | Can occur late and worsen heart problems [1]; low in a reported caffeine case [5] and in 16 of 34 tested dogs after chocolate [11] |
| Glucose | High, then sometimes low | In one dog: 142 mg/dL on arrival, 68 mg/dL the next day [5] |
| Lactate and blood gas | High lactate, acid blood | Reflects tremors, seizures and strain; 12.5 mmol/L on arrival in one dog [5] |
| CK and AST | High, sometimes very high | Muscle breakdown after tremors and seizures [5] |
| Urine | Dark (pigmented) urine | Can follow muscle breakdown [5] |
Caffeine leaves the body mainly through the kidneys, but methylxanthines and their breakdown products can be reabsorbed from urine through the bladder wall [4]. That is why the vet may place a urinary catheter and give fluids [1, 4]. Electrolytes and chemistry are checked on arrival and may be repeated in 2 to 3 days [4].
Care and outlook
There is no antidote for caffeine; care treats the signs [4, 5]. If the dog ate caffeine recently and has no signs yet, the vet may make it vomit [4]. Dogs with signs get hospital care: fluids, heart monitoring, medicines to calm tremors and control the heart rate, and cooling [2, 4]. In one severe case, the caffeine was removed from the blood with dialysis, and the dog fully recovered [5].
The outlook is usually good when the stomach is emptied in time, within 2 to 4 hours [6]. Most dogs in the guarana series recovered with supportive care, but 17% died or were euthanized; that product also contained ephedrine [3].
Related articles
All foods toxic to pets: toxic foods for dogs and cats. Other risks for dogs: xylitol and grapes and raisins.
En français : café et chien.
Questions to ask your veterinarian
- How much caffeine could my dog have taken with this product?
- Is my dog’s heart rate and rhythm normal on the ECG?
- Are potassium, glucose and lactate normal, and will they be rechecked?
- Is the CK high, and should we watch the urine color?
- How long should my dog be watched, at the clinic or at home?
Get your dog’s emergency blood results explained.
AI DiagAnimals reads potassium, glucose, lactate, CK and liver enzymes together with your laboratory’s intervals, and prepares the questions for your vet. The service opens soon: leave your email to be told first.
Frequently asked questions
What if my dog licked a small amount of coffee?
One or two licks of coffee, tea or soda are unlikely to poison most dogs [8]. Watch for restlessness, vomiting or a racing heart. Unused grounds, beans, pods, pills or a large sweet coffee drink with extra shots are a different matter [8]: call your vet or a pet poison line whatever the amount. Do not make your dog vomit at home: hydrogen peroxide damaged the stomach lining in every healthy dog tested [13].
Why does my dog love coffee?
Large coffee drinks with sweeteners and cream may be appealing to dogs [8], and the bitter taste of caffeine does not put them off [4]. That is why cups, grounds and pods should be kept out of reach.
How long does caffeine poisoning last in dogs?
Signs can start within 2 hours [4]. In 47 dogs that ate a guarana and ephedrine supplement, signs lasted up to 48 hours [3]; in severe cases they can last up to 72 hours [1, 4]. A large dose can also be cleared more slowly [5].
Are coffee grounds or pods dangerous for dogs?
Yes. Unused coffee grounds and beans can cause serious poisoning, unlike a lick of brewed coffee [8]. Coffee beans are one of the concentrated caffeine sources most linked to poisoning in dogs [5]. Call your vet or a pet poison line whatever the amount.
What is the most toxic thing a dog can eat?
There is no single answer: it depends on the product, the amount and the dog. Chocolate, which also contains caffeine, is the substance most often reported in dogs to the ASPCA Animal Poison Control Center [12]. Concentrated caffeine such as pills has killed dogs [4]. Our hub on toxic foods for dogs and cats lists the others.
Sources
- Hayes C. Chocolate Toxicosis in Animals. Merck Veterinary Manual, reviewed 2024, updated 2026. merckvetmanual.com/toxicology/food-hazards/chocolate-toxicosis-in-animals
- Tauer D. Toxicoses in Animals From Human Dietary and Herbal Supplements. Merck Veterinary Manual, reviewed 2024, updated 2026. merckvetmanual.com/toxicology/toxicoses-from-human-vitamins-minerals-and-dietary-supplements/toxicoses-in-animals-from-human-dietary-and-herbal-supplements
- Ooms TG, Khan SA, Means C. Suspected caffeine and ephedrine toxicosis resulting from ingestion of an herbal supplement containing guarana and ma huang in dogs: 47 cases (1997-1999). J Am Vet Med Assoc. 2001;218(2):225-229. doi.org/10.2460/javma.2001.218.225
- Tawde SN, Puschner B, Albin T, Stump S, Poppenga RH. Death by caffeine: presumptive malicious poisoning of a dog by incorporation in ground meat. J Med Toxicol. 2012;8(4):436-440. doi.org/10.1007/s13181-012-0254-y
- Gordon DS, Langston CE. Use of haemodiafiltration in the treatment of massive caffeine intoxication in a dog. Vet Med Sci. 2023;9(4):1460-1464. doi.org/10.1002/vms3.1147
- Cortinovis C, Caloni F. Household Food Items Toxic to Dogs and Cats. Front Vet Sci. 2016;3:26. doi.org/10.3389/fvets.2016.00026
- Kovalkovičová N et al. Some food toxic for pets. Interdiscip Toxicol. 2009;2(3):169-176. doi.org/10.2478/v10102-009-0012-4
- Pet Poison Helpline. Caffeine. petpoisonhelpline.com/poison/caffeine
- ASPCA Animal Poison Control Center. People Foods to Avoid Feeding Your Pets. aspca.org/pet-care/animal-poison-control/people-foods-avoid-feeding-your-pets
- US Food and Drug Administration. Spilling the Beans: How Much Caffeine is Too Much? fda.gov/consumers/consumer-updates/spilling-beans-how-much-caffeine-too-much
- Weingart C, Hartmann A, Kohn B. Chocolate ingestion in dogs: 156 events (2015-2019). J Small Anim Pract. 2021;62(11):979-983. doi.org/10.1111/jsap.13329
- Swirski AL et al. Companion animal exposures to potentially poisonous substances reported to a national poison control center in the United States in 2005 through 2014. J Am Vet Med Assoc. 2020;257(5):517-530. doi.org/10.2460/javma.257.5.517
- Niedzwecki AH et al. Effects of oral 3% hydrogen peroxide used as an emetic on the gastroduodenal mucosa of healthy dogs. J Vet Emerg Crit Care. 2017;27(2):178-184. doi.org/10.1111/vec.12558
- Merck Veterinary Manual. Serum biochemical analysis reference ranges. merckvetmanual.com/reference-values-and-conversion-tables/reference-guides/serum-biochemical-analysis-reference-ranges
Laboratory methods and reference intervals vary. This article explains; it does not diagnose. For a decision about your pet, use the original report and talk to your veterinarian. Our editorial policy.