Marijuana Toxicity In Pets

Last Year, Californians voted to legalize marijuana for recreational use.  Prior to this initiative passing, the plant was legal for use by those who had a medical use card.  Starting in 2018, the legalization of recreational marijuana promises to make the drug more plentiful - a move which may be celebrated by some owners, but may pose a hazard to their pets.

A Marijuana Plant. Owners should be aware that marijuana can be toxic to pets Many people are aware of the effects of marijuana on the human body, but they may not know how it affects pets. Our recent case load has proven that this is an important bit of knowledge.  In the past month alone, we have diagnosed and treated 3 cases of marijuana toxicity. 

When a pet presents with suspicious symptoms, diagnosis either comes when the owner is up front about the toxicity or possibly by way of a simple urine-dip test. Pets affected by marijuana usually present with more serious symptoms than the pleasurable effects sought by human users for several reasons.  First, pets usually ingest either the raw plant or other edible forms and they do not regulate their intake.  This results in the consumption of a large amount of THC.  Additionally, pets are usually of significantly smaller body weight than their owners so a much smaller amount is required to achieve dangerous effects.  Finally, pets do metabolize marijuana differently and it can take much longer for the effects to wear off.

Dogs represent the majority of marijuana toxicity cases, with cats following a distant second.  Other pet species can be affected, however their access is often more limited than free-roaming dogs and cats. Pets seem to actually like the taste of the raw plant and may seek it out even when it is not in cookie, candy or other “edible” form. 

Clinical Signs of Marijuana Toxicity in Pets

Clinical signs can occur within minutes, but may be delayed hours or even days due to the way pets digest and process the THC.  Mild cases present similar to medical or recreational human use: lethargy, altered response to visual or sound stimuli, and behavioral changes.  More severe cases display ataxia (walking as if drunk), low body temperature, low blood pressure, low heart rate, depressed respiratory rate, urinary incontinence, diarrhea, dysphoria, and seizuresVomiting and inappetance are also common in more severe ingestion cases, despite marijuana’s notorious appetite-stimulating effects.  In especially severe cases, coma and even death could result.

The symptoms of marijuana toxicity are similar to that of several other toxicities, so it is helpful to have confirmation of ingestion.  If an owner is aware that their pet has been exposed to marijuana (whether they know the pet has consumed it or not), it is vital that they let the veterinarian know as it can help make a positive diagnosis so treatments can begin.  If the owner is unaware of or will not admit to the pet’s exposure, diagnosis is made based on symptoms, a variety of (sometimes expensive) tests to rule-out other possible causes, and possibly a drug test.  It is important to note that drug tests used on pets are not perfect.  Pets can test negative if the drug is already metabolized and passed by the time a pet is seen or if a pet ingests such a small amount that the test does not register, even though the amount of the drug is enough to affect a small pet.

Treating Marijuana Toxicity in Pets

Treating marijuana toxicity depends on when the pet was exposed and on how severe symptoms are.  Like many toxicities, the veterinarian may recommend induction of vomiting followed by administration of activated charcoal (to absorb any remaining substance).  In severe cases, the doctor may also recommend a blood test to evaluate organ function (and to rule out other causes of symptoms).   After this, treatment is largely supportive.  The pet may be treated with IV fluids, thermoregulatory support (to help keep the body temperature up), GI supportive medications and hospitalization in a quiet space to decrease visual and auditory stimuli.

Most cases of marijuana toxicity in pets resolve with a positive outcome.  The patient is discharged when symptoms cease and they can hold down food and water.

It is important for owners to understand that marijuana is toxic to pets and can have very serious effects.  Toxicity is best prevented simply by being smart.  Either do not bring the substance home, or make sure to keep any form or amount of marijuana out of your pet’s reach.  Finally, if you suspect that your pet has ingested marijuana, be up front with your veterinarian.  They won’t judge you and it will help proper treatment begin quickly.

If you have questions about marijuana or other toxicities in pets, please call us at: (760) 634-2022

If you are concerned that your pet has ingested a toxic substance, you can also call the
Animal Poison Control Hotline: (888) 426-4435

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