THC Toxicity in Dogs & Cats: Signs, Diagnosis, and Treatment
As cannabis products become more widely available, THC toxicity is an increasingly important concern for pet owners. Tetrahydrocannabinol (THC), the psychoactive compound in marijuana, can affect both dogs and cats. Even small exposures may cause significant symptoms, and products such as edibles, concentrates, and oils can pose significant risks.
Understanding the warning signs of THC toxicity and knowing when to seek veterinary care can help protect your pet from potentially serious complications.
How Do Pets Get Exposed to THC?
Most cases of THC toxicity in pets occur when animals accidentally consume cannabis products. Dogs are particularly prone to eating discarded or unattended items because of their curious nature and strong sense of smell.
Common sources of exposure include:
Marijuana plant material, joints, and discarded cannabis products
Edibles, such as brownies, cookies, gummies, and chocolates
THC oils, tinctures, and concentrated cannabis products
Cannabis-infused butter or other foods
Edibles can be especially dangerous because they may contain very high concentrations of THC and pets will often consume an entire package if given the opportunity. Edibles often contain fats to aid in the absorption of THC in people, something that also occurs in animals. Pets who consume cannabis plants, without also ingesting fats, will have less absorption than eating a product with THC and fat. Edibles may also contain additional toxic ingredients, including chocolate, xylitol, or large amounts of fat. Cats may also be exposed by ingesting cannabis products or grooming residue from contaminated fur.
Signs and Symptoms of THC Toxicity in Pets
THC affects the central nervous system, and symptoms can develop within 30 minutes to several hours after exposure, depending on the product and amount of THC ingested.
Common signs of THC toxicity in dogs and cats include:
Uncoordinated walking, stumbling, or difficulty standing
Lethargy, unusual sleepiness, or disorientation
Dilated pupils and sensitivity to touch, light and sound
Urinary incontinence or dribbling urine
Vomiting or excessive drooling
Tremors, agitation, or abnormal behavior
Changes in heart rate or body temperature
In severe cases, pets may develop profound depression of the central nervous system, seizures, abnormal breathing, or a decreased level of consciousness. Although most pets recover with appropriate supportive care, complications can be life-threatening, particularly when other toxic substances are involved.
If you suspect your pet has consumed THC, contact a veterinarian promptly. Do not wait for symptoms to develop, and never attempt to induce vomiting unless specifically directed by a veterinary professional.
How Is THC Toxicity Diagnosed?
Veterinarians typically diagnose THC toxicity using a combination of medical history, physical examination, and clinical signs. Because symptoms can resemble other conditions, including low blood sugar, liver disease, neurologic disease, and exposure to other toxins, additional testing may be necessary.
Diagnostic options may include:
History and physical examination: Information about possible exposure, the product involved, and the timing of ingestion helps guide treatment.
Bloodwork: A complete blood count (CBC) and chemistry panel may be recommended to evaluate blood sugar, liver function, overall health, organ function, and potential complications.
Blood glucose testing: Helps identify low blood sugar, which can cause similar neurologic symptoms.
Additional diagnostic testing: Depending on the pet's condition, veterinarians may recommend urine testing, blood pressure monitoring, electrocardiography (ECG), or other tests to rule out alternative causes.
THC Urine Drug Screen: Human urine drug screening tests may be helpful in the diagnosis. While these tests often have false negatives because pets can have signs of THC toxicity before sufficient quantities are present in the urine for the test to be positive, a positive test does confirm exposure to THC. This is why treatment decisions are made based on history, physical exam and clinical picture, instead of a positive test result.
Treatment Options for THC Toxicity
There is no specific antidote for THC poisoning in pets. Treatment focuses on keeping the animal safe while the body metabolizes the drug and promoting the body to excrete/eliminate the drug. Options depend on the amount ingested, the timing of exposure, and the severity of symptoms.
Veterinary treatment may include:
Decontamination: While not typically performed, if ingestion occurred recently and the pet is not showing symptoms, a veterinarian may consider inducing vomiting in a controlled setting. This is generally unsafe for pets that are already sedated or uncoordinated because of the risk of aspiration.
Fluids: While fluids help support the body and the blood pressure, some THC and THC metabolites are excreted in the urine. The administration of fluids helps promote urinary excretion. In cases that are not severe or the amount of THC ingested is not enough to be life-threatening, subcutaneous fluids are usually given. In severe cases or when potentially lethal doses have been ingested, IV fluids are recommended.
Symptom management: Medications may be used to control vomiting, tremors, agitation, or seizures when necessary.
Temperature and cardiovascular monitoring: Veterinary staff may monitor body temperature, heart rate, blood pressure, and breathing.
Hospitalization and nursing care: More severely affected pets may need close monitoring, oxygen support, or assistance maintaining a safe body position. Intravenous lipid emulsion therapy may be considered in selected severe cases.
Most pets recover within 24 hours with appropriate care, although recovery time varies with the exposure and severity of illness. Signs can sometimes last for up to 3 days.
How to Prevent THC Poisoning
Prevention is the best protection for your pet. Store cannabis products, edibles, oils, and concentrates in sealed containers secured where pets cannot reach them. Dispose of cannabis waste safely, keep pets away from unattended food and smoking materials, and never intentionally give pets cannabis products.
Concerned Your Pet Consumed Cannabis or THC?
If your pet may have ingested THC, contact your veterinarian or an emergency veterinary hospital immediately. Prompt veterinary attention can make a significant difference. Being honest about the product and estimated amount consumed helps your veterinary team choose the safest and most effective treatment for your dog or cat.
You can also call the Pet Poison Helpline at 855-764-7661 or the ASPCA Animal Poison Control Center at 888-426-4435 (fees may apply).
Call us at (818) 296-0700 in Burbank or (323) 302-5200 in Koreatown to speak with a member of our care team. We’re here to help for your furry loved one’s medical needs!
