Yes, cloves are toxic to dogs. The danger comes from eugenol, the compound that gives cloves their strong, warm scent. Eugenol is directly toxic to liver cells in dogs, and in concentrated forms like clove essential oil, even a small amount can cause serious harm. The level of risk depends heavily on whether your dog encountered a whole dried clove, ground spice, or essential oil.
Why Cloves Are Dangerous for Dogs
Eugenol makes up roughly 70 to 90 percent of clove essential oil, and it has direct cytotoxic activity, meaning it kills cells on contact at high enough concentrations. In lab studies using canine liver cells, eugenol proved lethal to those cells at a concentration of just 0.165 mg/ml. Clove-leaf oil was similarly toxic at 0.185 mg/ml. These are very low thresholds.
The liver damage eugenol causes looks similar to what happens in acetaminophen or iron poisoning: acute destruction of liver tissue. In severe cases, this progresses to liver failure. Eugenol also affects the nervous system and blood sugar regulation. Human overdose cases involving 10 to 30 mL of clove oil have caused agitation, loss of consciousness, dangerous drops in blood sugar, and coma within hours. Dogs are smaller and more sensitive, so the threshold for harm is lower.
Whole Cloves vs. Clove Oil
There’s a significant difference in risk depending on the form your dog got into. A single whole dried clove bud that a dog swallows without much chewing is unlikely to cause a medical emergency. Whole buds are hard to digest, so the eugenol they contain isn’t fully released. That said, if a dog chews and swallows several whole cloves, enough eugenol can be absorbed to cause problems.
Ground clove spice is more concerning because the eugenol is more readily available for absorption. A pinch that fell on the floor is unlikely to be dangerous for a large dog, but a tablespoon or more could cause gastrointestinal irritation and potentially more serious effects, especially in a small breed.
Clove essential oil is by far the most dangerous form. It’s highly concentrated, and a single drop of undiluted clove oil can be enough to poison a medium-sized dog. If your dog licked or ingested clove essential oil, treat it as an emergency regardless of the amount.
Symptoms of Clove Poisoning
Signs of toxicity can appear within a few hours of exposure. What you see depends on how much eugenol your dog absorbed and whether the exposure was oral, topical, or inhaled. Watch for:
- Gastrointestinal signs: vomiting (sometimes with a noticeable clove smell), drooling, loss of appetite, diarrhea
- Neurological signs: lethargy, weakness, muscle tremors, uncoordinated walking, depression
- Respiratory signs: labored breathing, panting, coughing, or wheezing
- Skin and mouth irritation: redness or chemical burns on the lips, gums, tongue, or skin; pawing at the mouth or face
You may also notice the scent of cloves on your dog’s coat, breath, or around their mouth. If your dog seems fine but you know they ingested clove oil, don’t wait for symptoms. Liver damage can develop before outward signs become obvious.
Risks of Diffusing Clove Oil
Diffusers that release a fine mist of essential oil and water into the air create two exposure routes. Your dog can inhale the aerosolized oil directly, and the mist can settle on their fur and be ingested when they lick or groom themselves. Dogs with asthma, allergies, or other respiratory conditions are at higher risk of breathing problems from diffused clove oil.
If you use a diffuser with clove oil, keep it in a room your dog can’t access, and make sure the area is well ventilated. Passive diffusers like reed sticks are generally less risky than active ultrasonic or nebulizing diffusers, but they still expose pets to volatile compounds. The safest approach is to avoid diffusing clove oil in a home with dogs.
What to Do if Your Dog Ingests Cloves
For a dog that ate one or two whole dried cloves, monitor closely for vomiting, drooling, or lethargy over the next 12 to 24 hours. Most dogs in this situation will be fine, but call your vet or a pet poison hotline if symptoms develop.
For any exposure to clove essential oil, whether swallowed, applied to the skin, or licked off a surface, contact your veterinarian or the ASPCA Animal Poison Control Center (888-426-4435) immediately. Don’t induce vomiting unless specifically instructed to do so, because clove oil can cause additional burns to the esophagus on the way back up. If the oil is on your dog’s skin or fur, wash it off gently with dish soap and warm water to prevent further absorption.
Treatment for clove oil poisoning is primarily supportive. Because eugenol causes direct liver damage, your vet will likely run blood work to check liver function and may provide IV fluids, medications for nausea, and liver-protective treatments. Dogs that receive prompt care after small exposures generally recover well. Large ingestions of concentrated oil carry a more serious prognosis, particularly if liver damage is already underway by the time treatment begins.