Marijuana ingestion by pets, whether accidental or intentional, is nothing new to most veterinarians. But with the loosening of medicinal marijuana laws and recent legalization of marijuana in Colorado, the frequency and severity of intoxications are definitely on the rise. The Animal Poison Control Center operated by the American Society for the Prevention of Cruelty to Animals (ASPCA) reports a tripling in calls related to marijuana ingestion over the last 10 years. Calls received reported ingestions primarily in dogs and of all shapes and sizes from one pound Yorkshires to 130-pound Great Danes. Personally, I am seeing cases regularly enough to warrant this article. The psychoactive ingredient in marijuana is delta 9-tetrahydrocannabinol, more commonly called THC. Regular marijuana is typically 1 to 8 percent THC. The newest incarnation of edible products can contain THC levels of 10 percent or higher and often these products are made with chocolate or infused butters, which can cause secondary complication such as pancreatitis. Worse yet is the fact that these edible candies are often meant to be taken by the user over periods of several days and an unsuspecting dog will devour the entire product at once causing rapid and severe intoxication.In dogs, clinical signs typically begin 30 to 90 minutes after ingestion. Because THC is stored in the body's fat deposits, the effects of marijuana ingestion can last for days. Classic signs of marijuana toxicity in dogs include ataxia or stumbling, listlessness, disorientation, slow reflexes and hypersensitivity to touch, sound, or light, dilated pupils and a slow heart rate - similar to what you'd expect in a person under the influence. Another typical sign in dogs is urinary incontinence (fortunately not so with people). Typically owners report that "my dog is just acting very weird." Because marijuana toxicity can look similar to intoxication with numerous other drugs, it is important for any relevant information to be given to the veterinarian if the pet is to be helped; veterinarians are not obligated to report drug intoxications to the police. This goes for any other medication or recreational drug as well. Urine testing similar to that done with humans can be done in dogs to confirm suspected cases of marijuana intoxication. Veterinary treatment might involve induction of vomiting if less than 30 minutes have passed since the marijuana has been eaten. But once symptoms have started the nausea control properties of THC make it difficult to induce vomiting. Also, vomiting can be dangerous in a patient that is extremely sedated, as vomit can be inhaled and cause a serious and potentially deadly aspiration pneumonia. Administering a liquid form of activated charcoal can help speed elimination of toxins so that when the charcoal passes from the patient, the toxins pass too. Many patients are then sent home to sleep off residual effects of the drug. In more serious cases, fluid support and keeping the patient warm may also be needed in treatment. If the patient has lost consciousness, more intense observation and support is needed. The chance of fatality is statistically small but possible such as when a patient has an extremely low heart rate or can't swallow or stand. These patients obviously require a hospital stay and typically intravenous fluids and extensive nursing care. In rare instances, patients may remain unconscious for many hours.Hopefully, by learning about animals' propensity to get into marijuana in all its forms, pet owners will do a better job keeping it out of reach. Email questions to firstname.lastname@example.org. Veterinarians Charlie Meynier and Tom Suplizio practice at the Vail Valley Animal Hospital and ER, with locations in Eagle-Vail and Edwards. On-call vets are available after hours, and an emergency hospital in Edwards is open 24 hours a day. For more information, call 970-926-3496 or visit www.vailvalleyanimalhospital.com.