Marijuana Toxicity in Pets



Since the passage of two amendments to the state constitution in Colorado (Amendment 20 in 2000, allowing medical use of marijuana and Amendment 64 in 2012, allowing recreational use), exposure of pets to marijuana in our area has increased, and toxicity from these products can be serious in animals.

Pet exposure occurs most frequently in dogs, but cats and other pets are also at risk. Different forms of marijuana can contain drastically variable levels of THC (short for tetrahydrocannabinol, the main psychoactive component in marijuana and other cannabinoids). Exposure can occur to marijuana plants, loose leaf marijuana, edibles, oils, or second-hand smoke.

For pets who have ingested items containing THC or inhaled marijuana smoke, signs of toxicity can include nervous system changes, such as stumbling, sleepiness, mental dullness, and disorientation; rarely, an affected pet may show signs of CNS stimulation. Severely affected pets may go into a coma. Dogs usually display urine dribbling as a sign, and their third eyelids are usually prominent. Affected pets may also show an extreme sensitivity to stimuli such as touch or sound. Cannabinoids can cause vomiting, but this is rarely seen as they usually produce profound anti-nausea effects.

If a pet has consumed a large amount of edible product (i.e. – brownies, candy, cookies, etc.) or plant material, gastric lavage (aka “stomach pumping”) may be necessary, and it is important to seek veterinary care as soon as possible. Activated charcoal may be administered orally to minimize further absorption of THC. In more severely affected cases the pet may need to be hospitalized for supportive care, which can include warming, oxygen, IV fluids, and sedation if needed. There is no specific antidote for THC toxicity.

While marijuana toxicity is rarely fatal, it can indeed be serious, and immediate veterinary care is always best. Recovery time for pets is highly variable, but most pets are back to normal within 12 to 24 hours. If you have any specific questions about marijuana toxicity, ask your veterinarian or veterinary technician.

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  • Kristin Hrenchir, DVM

Leptospirosis: To Vaccinate or Not To Vaccinate…


Earlier in 2015, you may have read about a perceived uptick in cases of leptospirosis, especially in urban and suburban dogs. You might have asked yourself, what is leptospirosis? And then, is there anything I can do to help protect my dog? The good news is, yes, there is! And now is an important time to review the facts.

Leptospirosis is a species of spiral or corkscrew-shaped bacteria, known as spirochetes. The bacteria are transmitted through contact with mucous membranes, such as the mouth or eyes, or with damaged skin. The bacteria are often passed in the urine of wildlife, such as deer, foxes, and raccoons and are sometimes found in standing water on trails or in greenspaces or backyards.  An unsuspecting dog may then drink from a puddle contaminated with urine containing the bacteria and contract the disease.

Almost all mammals, including humans, are susceptible to the disease, which can cause liver and kidney failure, eye problems, and anemia, among other things. Cats, however, appear to be relatively resistant to the negative effects of the disease, but can remain carriers after infection.

Clinical signs of the disease include fever, decreased appetite, increased urination and water consumption, lethargy, vomiting and diarrhea. If you notice these in your dog, you should seek immediate veterinary care. Recommended diagnostics may include a general blood panel, x-rays, a urinalysis, urine culture, and/or leptospirosis testing.

Prevention of the disease is aimed at informing pet owners of the risks and vaccinating at-risk patients.  Traditionally, vaccination efforts have focused on those patients most at risk of contracting the disease like hunting dogs, dogs who hike or camp with their owners, or dogs who live on farms or in other rural areas. In Colorado, however, we can find wildlife in almost any place, even suburban or urban areas. As such, if you think your pet is at risk, you should have them vaccinated immediately.

Initially, your dog will need a booster vaccination at 4 weeks after the first vaccination. From then on, vaccination is performed annually. Unfortunately, the vaccine only protects against 4 of the 8 serovars, or strains, of leptospirosis that effect dogs, so it is not 100% effective. The vaccine may also carry a slightly higher risk of vaccine reactions, similar to a reaction from a bee sting for someone who is allergic to bees. These reactions are rarely, if ever, life-threatening when treated appropriately, as opposed to the disease, which is often fatal to dogs. Despite these 2 potential drawbacks of the vaccine, it is the best protection currently available and is strongly recommended for at-risk patients living in Colorado.

As always, if you have any other specific questions about leptospirosis, your dog’s risk, or the vaccine, ask your veterinarian or veterinary technician. Visit for more information about our hospital and services.

  • Joseph Conrad