Article reviewed for Accuracy by Dr. Manthar.

Looking for a vet’s advice on common symptoms of cannabis toxicity in dogs? Look no further, as we have got you covered!
Cannabis Toxicity in Dogs: A Vet’s Guide
Did you know that in the past five years, canine cannabis toxicity has increased by 300%? According to the ASPCA’s Animal Poison Control Center, this is a very alarming situation for pet owners. Pets, particularly dogs, exhibit a range of symptoms when they ingest cannabis. Each symptom reflects how THC interacts with a pet’s body, disrupting normal physiological functions.
Recognizing these THC toxicity symptoms and understanding their causes can help pet owners take prompt action and seek appropriate veterinary care to ensure their pet’s safety and well-being. In this guide, I will discuss common symptoms of THC poisoning in dogs.
Why is Cannabis Toxic to Dogs?
THC is the most active constituent of the marijuana plant and can cause high toxicity in dogs. It travels all the way to the dog’s nervous system and alters the serotonin and dopamine levels in the brain. As a result, your dog may face severe neurological and health issues.
Neurological Symptoms of Marijuana Toxicity in Dogs
THC’s influence on the brain can lead to overstimulation of the nervous system, causing the following involuntary and often violent symptoms:
Ataxia (Uncoordinated Movements)
Ataxia refers to a lack of muscle coordination that can affect voluntary movements such as walking, standing, and even eye movements. Pets with ataxia appear wobbly and unsteady. This happens because THC affects the cerebellum, the part of the brain responsible for coordinating movement and balance. The disruption in normal neural communication results in a lack of coordination, making it difficult for the pet to navigate its environment safely.
Tremors or Seizures
If you notice involuntary, rhythmic muscle contractions, your dog might be experiencing a seizure, which is a sudden, uncontrolled electrical disturbance in the brain. Seizures involve intense convulsions and can be accompanied by a loss of consciousness and uncontrolled muscle movements. Moreover, tremors can manifest as repetitive muscle twitches or more severe shaking.
Hyperactivity or Agitation
Hyperactivity involves excessive and inappropriate levels of activity, while agitation includes restlessness and an inability to stay calm. Pets may show signs of anxiety, such as pacing, panting, whining, or excessive vocalization. THC can overstimulate the brain’s neurons, leading to increased energy levels and restlessness, making it difficult for the pet to settle down.
Lethargy or Excessive Sleepiness
Lethargy is characterized by extreme tiredness and a lack of energy, while excessive sleepiness means prolonged drowsiness. Affected pets may sleep more than usual, have difficulty waking up, and show disinterest in their surroundings. THC acts as a depressant on the central nervous system, leading to sedation and significant fatigue.
Dilated Pupils
Dilated pupils can make the eyes appear dark and wide. This symptom is often accompanied by a decreased response to light, meaning the pupils do not constrict as they normally would when exposed to bright light.
Hypersalivation
Pets may drool more than usual, with saliva potentially pooling around the mouth or dripping from the mouth. This can be a result of nausea or a direct effect of THC on the salivary glands.
Gastrointestinal Symptoms of Toxicity in Dogs
Vomiting
Vomiting can occur repeatedly and may include food, liquid, and sometimes bile. It is the body’s way of trying to eliminate the ingested toxin.
Diarrhea
Diarrhea can occur as the gastrointestinal system reacts to the ingested toxin. It may be accompanied by abdominal discomfort and an increased frequency of bowel movements.
Cardiovascular Symptoms of Cannabis Toxicity in Dogs
Cannabis toxicity in dogs can lead to a range of cardiovascular symptoms. These symptoms can vary depending on the amount of cannabis ingested and the size of the dog.
Bradycardia
Bradycardia, or a decreased heart rate, occurs when a dog’s heart beats more slowly than normal. Marijuana ingestion in dogs triggers this condition due to its effects on the nervous system and cardiovascular system.
In a healthy dog, the heart rate is typically between 60 and 140 beats per minute, depending on the size and breed of the dog. When a dog experiences bradycardia as a result of cannabis toxicity, their heart rate can drop significantly below this range. This reduced heart rate can lead to inadequate blood flow throughout the body, which can lead to lethargy, weakness, and fainting.
Hypotension
Hypotension, or low blood pressure, occurs when the force of blood against the walls of the arteries is lower than normal. In dogs, cannabis toxicity can lead to hypotension due to the vasodilatory effects of the cannabinoids found in cannabis. This means that the blood vessels widen, causing a drop in blood pressure. It can cause dizziness, weakness, and fainting and can be particularly dangerous if it leads to decreased blood flow to vital organs.
Urinary Problems Faced by Affected Dogs
Pets may dribble urine without control, often leaving wet spots where they rest. This can be embarrassing for the pet and frustrating for the owner, but it is a sign of the pet’s lack of control over their bodily functions due to the toxicity.
Diagnosis
As veterinarians, we usually diagnose cannabis toxicity in dogs based on the following signs:
- Clinical Signs: Observing the symptoms exhibited by the pet.
- History: Obtaining a detailed history from the pet owner about possible exposure to cannabis.
- Laboratory Tests: In some cases, blood or urine tests might be conducted to detect the presence of THC (the psychoactive compound in cannabis).
Treatment
Unfortunately, there is no specific antidote for cannabis toxicity, so treatment is supportive and symptomatic. As a clinician veterinarian with over 10 years of experience, I have recently seen a surge in marijuana toxicity cases among dogs. The most effective treatment methods include induced vomiting to prevent further absorption of THC. Moreover, IV fluids can help maintain hydration, support blood pressure, and assist in the excretion of toxins.
In very extreme cases, like the one I came across a few months ago, where a dog was extremely poisoned, it requires the pumping of the dog’s stomach with activated charcoal. It is given every 6 to 8 hours to neutralize the harmful effects of THC on dogs.
Prognosis
With prompt veterinary care, the prognosis for pets with cannabis toxicity is generally good. Most pets recover fully within 24 to 72 hours. However, in rare cases, especially with large ingestions or underlying health issues, complications can occur, but fatalities are uncommon.
How Do You Prevent Dogs from Developing Cannabis Toxicity at Home?
In order to keep your pets safe from marijuana toxicity, as a vet, I request that you all keep edible cannabis away from the reach of your dog. In addition, it is important to educate your family and friends about the hazards of THC toxicity in pets. Make sure to keep your dog in a separate place when you vape or smoke marijuana.
Final Words
Cannabis toxicity in pets is a serious but entirely preventable issue. As cannabis products become more prevalent in households, it is crucial for pet owners to be vigilant in keeping these items securely out of reach.
Recognizing the signs of cannabis ingestion early and seeking immediate veterinary care can make all the difference. In most cases, with prompt and appropriate treatment, pets can make a full recovery.
FAQs
Is Weed Toxic to Dogs?
Yes, weed (cannabis) is toxic to dogs. The toxic effects are primarily due to THC (tetrahydrocannabinol), the psychoactive compound in cannabis. Dogs are more sensitive to THC than humans, and even a small amount can lead to serious symptoms.
Can THC Kill a Dog?
THC is highly toxic and can potentially kill a dog, especially if ingested in large amounts. Unlike humans, dogs have more cannabinoid receptors in their brains, making them more susceptible to the effects of THC. Even small amounts of THC can cause significant symptoms, such as altered mental state, uncoordinated movements, drooling, a low heart rate, low blood pressure, and potentially life-threatening conditions.
How Long Does THC Toxicity Last in Dogs?
The duration of THC toxicity in dogs can vary depending on the amount ingested and the size of the dog. Generally, symptoms can last anywhere from 12 to 24 hours, but in some cases, they may persist for up to 72 hours.