Marijuana

Cannabis is a genus of flowering plants comprised of three species: Cannabis sativa, Cannabis indica, and Cannabis ruderalis. Originally native to Central Asia and South Asia, the plants can now be found throughout the world, primarily as a product of the illegal drug trade. In appearance the leaves are palmately compound or digitate, with serrate leaflets. The first pair of leaves usually have a single leaflet, the number gradually increasing up to a maximum of about thirteen leaflets per leaf (usually seven or nine), depending on variety and growing conditions. At the top of a flowering plant, this number again diminishes to a single leaflet per leaf. The lower leaf pairs usually occur in an opposite leaf arrangement and the upper leaf pairs in an alternate arrangement on the main stem of a mature plant.

Cannabis has long been used for fiber (hemp), for seed and seed oils, for medicinal purposes, and as a recreational drug. Industrial hemp products are made from Cannabis plants selected to produce an abundance of fiber. To satisfy the UN Narcotics Convention, some Cannabis strains have been bred to produce minimal levels of THC, the principal psychoactive constituent responsible for the "high" associated with marijuana. Marijuana one the other hand consists of the dried flowers of Cannabis plants selectively bred to produce high levels of THC and other psychoactive cannabinoids. Various extracts including hashish and hash oil are also produced from the plant.

Known by many names, Marijuana needs very little introduction as it is the third most popular recreational drug in America (behind only alcohol and tobacco). As a result the vast majority of pet toxicity cases involve dogs inadvertently eating its owner’s stash of marijuana. Luckily, however, the ingestion of marijuana, while not good for a pet is rarely if ever life threatening.

The plants psychoactive ingredient is delta 9-tetrahydrocannabinol, more commonly called “THC.” Regular marijuana is typically 1-8% THC while hashish, made from the flowering tops of the plant and its resins, can contain up to 10% THC. Unfortunately little research has been “officially” conducted into the possible effects of severe marijuana toxicity on a pet. As a result the LD50 (amount that needs to be ingested to kill half of those who ingest it) has not been established in dogs or cats. The small amount of research that has been completed showed that oral doses of delta 9-THC and delta 8-THC as high as 3,000 to 9,000 mg/kg were not lethal, and all dogs recovered within 24 hours of ingestion. To put this into perspective, the non fatal ingestion of 3000 mg/kg of THC by the average dog would be comparable to a 150-pound human eating approximately 46 pounds (21 kilograms) of 1%-marihuana or 10 pounds of 5% hashish at one time.

In most cases the symptoms of ingestion of marijuana by a pet are similar to those of ingestion by a human. Clinical signs will typically begin 30-90 minutes after ingestion and include loss of coordination, listlessness, dilated pupils, lethargy, conjunctival injection (reddening of the eyes), dilated pupils, bradycardia (a slower than normal heart rate), altered response to visual or verbal stimuli and behavior changes. More severe cases can present with hypothermia, hypotension, severe difficulty standing, staggering, nearly falling over and suddenly catching balance to right themselves or falling over completely, inappetance, hypersalivation, vomiting, , urinary incontinence, diarrhea, near complete loss of voluntary muscle control to the extremities, and dysphoria (vocalization). Coma and death while basically unheard of are theoretically possible in exceptionally severe cases. Death, however, would more than likely be the result of the psychoactive ingredient in marijuana exasperating a previously unknown medical condition or acting in conjunction with other unknown toxins. An opinion substantiated by a 2002 peer-reviewed paper entitled “Marijuana exposure in animals” by Caroline W. Donaldson, DVM which states:

“Out of more than 250 cases of accidental marijuana ingestion reported to the ASPCA APCC, two deaths were reported. In one cat, exposure to multiple agents was possible, and the results of a gross necropsy revealed that the animal probably died of complications of cardiomyopathy. The second death reported was a horse with signs attributed to colic, but a gross necropsy was not done. The prognosis is favorable for symptomatic animals with no secondary complications, such as aspiration pneumonia. With supportive care, these animals usually recover within 72 hours.”

It is important to note that marijuana toxicity can look similar to and be confused with intoxication by any number of other sedatives. As a result it is imperative that you are certain that it is in fact marijuana toxicity that is affecting the pet and not toxicity from an unknown substance. In the event you are not certain, it is possible to use a drug test kit to test for the presence of marijuana metabolites in urine. Available at most drug stores for human use, these kits can be used to test the urine for a wide range of recreational drugs. Unfortunately, a relatively large volume of urine is needed to perform the test which could make it unusable when dealing with a small pet. Additionally the process of obtaining a urine sample from a pet in the home environment may prove too difficult for the average pet owner. Lastly, human test kits have shown the propensity to display false negative test results when performed on pet urine. In most cases, a confirmation of marijuana intoxication will be based on history and obvious indications that the pet may have ingested the plant.