Marijuana and Pets

Written on June 08, 2018 by Dr. Beth Eisenberg, DVM, DACVECC Hospital: Ethos Veterinary Health

With its legalization, marijuana use has become a more frequently discussed topic amongst the veterinary community.  There are potential health benefits, but little has been proven or even studied for use in animals in the veterinary industry. When ingested by pets, marijuana can cause some concerning symptoms. Pet owners should be vigilant of possible instances of exposure, and always express their suspicions with their veterinarian if they suspect ingestion. Support and treatment can be administered much quicker if the doctor knows the cause of a patient’s symptoms.

What’s the buzz with marijuana?

Marijuana and hemp are the two most common products of the Cannabis sativa plant. Marijuana is derived from the leaves and flowers of the plant, whereas hemp comes from the seeds and fibrous stalks. The major difference between marijuana and hemp is the concentration of chemicals called cannabinoids within each product. Although there are many chemical compounds within the cannabis plant, THC and CBD are the cannabinoids that are most studied. In human and animal bodies, there are 2 main receptors for cannabinoids called CB1 and CB2. When stimulated, the CB1 receptors in the brain alter body posture, muscle control, and the sensations of hunger, memory and fear. Compared to humans, dogs have a higher concentration of receptors in the brain in areas that control body posture and balance or coordination. THC and CBD bind the receptors differently, leading to diverse effects within the body.

Typically, it is THC that causes the classic psychoactive symptoms of marijuana exposure (“the munchies,” incoordination, the “high” feeling, etc.) CBD, on the other hand, works by different mechanisms and causes more medicinal marijuana effects (pain relief, anti-anxiety, anti-oxidant, etc.)

The concentrations of THC and CBD can be altered in cultivated cannabis plants so that the desired effects can be maximized. By definition, hemp products contain a higher concentration of CBD compared to THC. Legally, hemp cannot contain more that 0.3% THC concentration. Alternatively, marijuana products have a higher concentration of THC compared to CBD, though the ratio varies. Marijuana may contain up to 25% THC. Synthetic cannabinoid products also contain variable levels of THC and CBD, often in much higher concentrations than plant-derived products.

What are the benefits of marijuana?

Proven Health Benefits in Humans:

Medical marijuana has many proven and suspected benefits in humans. These may include, but are not limited to:

  • Pain control
  • Appetite stimulation
  • Seizure control
  • Modulation of mood and anxiety disorders

Routes of administration can include capsules, edibles, inhalation of smoke or vapors, mucosal sprays, and liquids. Currently, there are no FDA-approved plant-based cannabinoid products in the United States, though several are in the process of testing for approval. There are three synthetic cannabis (THC) products that have been approved by the FDA for specific uses in humans. Cannabis products are all labelled as controlled substances by the Drug Enforcement Agency. Naturally-derived THC products are classified as Class I drugs, along with heroin and LSD, which are considered the most dangerous substances by the DEA. Human medical doctors practicing in states that have legalized medicinal or recreational marijuana are not permitted to prescribe or dispense natural THC products, but they may recommend or offer a referral to a medicinal marijuana program or dispensary. Despite individual state laws regarding natural marijuana use, the Federal government does NOT recognize legal marijuana use and the Department of Justice is legally able to pursue prosecution in any state. As of writing, there are no legal provisions for veterinarians regarding the use, discussion, or recommendation of cannabis products of any kind.

Potential Health Benefits in Pets:

As in people, there is interest in cannabis products for medical uses in companion animals. Some reported benefits may include:

  • Chronic pain control
  • Seizure control
  • Anti-anxiety
  • Relief of glaucoma pain and dermatologic conditions

AP Photo/David Zalubowski

A recent safety study of a CBD product intended for seizure control in dogs was complete, showing measurable blood levels of CBD and an acceptable safety profile. Several clinical studies are currently underway at Colorado State University for dogs with seizure disorders and arthritis. A recent pilot study at Cornell, that has not yet been published, evaluated a specific CBD oil product for the management of arthritis pain in dogs.  In this randomized, placebo-controlled study, dogs treated with CBD oil showed improvement in their pain and mobility scores.  An elevation in liver values was documented.  The authors are clear in stating that more research needs to be done to determine the usefulness and safety of CBD in dogs and cats.  Despite lack of scientific evidence, there is likely value in cannabis products, specifically CBD, in the management of a number of veterinary disease processes. The most important aspect of intentional marijuana use in dogs is that CBD is considerably safer compared to THC, but many products intended for humans have high concentrations of THC. If choosing to treat a pet with cannabis, it’s strongly recommended to pick a product that discloses the concentration of CBD and is intended for animals rather than people. As of yet, there are no studies that determine the proper dose or frequency of any cannabis-product for treatment of any particular condition. Until we have more supportive literature, veterinarians can’t effectively guide therapy with cannabis products.

Marijuana Toxicosis

Accidental or intentional exposure to marijuana products high in THC can have serious adverse effects in dogs. Compared to people, dogs show symptoms of toxicity even with relatively low doses of THC. Symptoms of marijuana (THC) toxicosis in dogs can include:

  • Drooling
  • Unsteady gait or stance
  • Dull or confused mentation
  • Dribbling urine, dilated pupils
  • Tremors or twitching
  • Vomiting

Affected dogs may also be hyperreactive to sounds and being touched or restrained. Severe symptoms can mimic much more serious neurologic diseases, including encephalitis (inflammation of the brain). Although most cases are mild and self-limiting, higher doses lead to more severe symptoms and deaths have been reported after ingestion of very large amounts of THC-containing oils or butters (ex. brownies or cookies). Since chocolate is commonly used as a flavoring in marijuana edibles, dogs are at risk for both THC and chocolate poisoning after ingestion. Synthetic marijuana drugs or medications are likely the most dangerous to animals because of the high concentration of THC.

What do you do if your pet has been exposed?

If an animal is known or suspected to be exposed to THC-containing products, immediate veterinary attention is recommended. It’s very important to be honest with the veterinary team evaluating your pet. Since marijuana toxicosis can mimic very serious neurologic diseases, it’s possible that costly tests and a poor prognosis would be discussed, unless an owner is honest about the possibility of exposure.

The diagnosis of marijuana toxicosis is usually based on owner-reported exposure, symptoms, and clinical suspicion. There are urinary drug tests that may be accurate in dogs, but differences in drug metabolism in dogs compared to people can lead to falsely negative results. Treatment of marijuana toxicosis is usually supportive care with fluids and, if indicated, antinausea medication. Sometimes treatment with an IV lipid emulsion can help reduce the severity of
symptoms and hasten recovery. Most dogs admitted to the hospital for care are fully recovered within 24 hours of exposure.

 

In summary, while there is potential for medicinal use of marijuana in animal patients, it is a possibility that requires further exploration.  There have been multiple instances of marijuana-induced harm in animals, and thus pet owners should be careful to avoid any accidental exposure.  If your pet is exposed, it is recommended that you seek veterinary help immediately.

 

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