When Tank, a 3-year-old male pit bull mix, arrived with his owner at a veterinary office in Humboldt County, his jaws packed with white powder, it was clear that something was seriously wrong.
Earlier, Tank had mysteriously consumed an entire box of baking soda -- odd behavior, even for an animal with famously indiscriminate eating habits.
But more disturbing was Tank's demeanor. He sat trembling, his front legs stuck out at an awkward angle, his dilated eyes fixed on a distant point. A check of the heart revealed a coma-like 32 beats per minute, far below normal.
Joseph Humble, the attending veterinarian, suspected poisoning. But from what? The dog's owner pleaded ignorance. Tank, distracted, wasn't saying.
A few minutes later, the mystery was solved. "The guy called me right back and said, 'Doc, I know what happened,' " Humble recalls. " 'The dog ate some pot -- kind of a lot of pot.' "
Marijuana's action on humans is well understood: Once its psychoactive agent, tetrahydrocannabinol, better known as THC, is carried from the lungs or stomach by blood to the brain, it binds to nerve cells and activates the brain's pleasure centers. Effects include sensory sensitivity, motor impairment and an increased desire for Doritos.
The plant's effect on canines is considerably less benign. Even a few grams can cause staggering, vomiting, urinary incontinence and, in severe cases, seizures and coma. "Some people may enjoy pot, but I assure you dogs do not," Humble says.
Although no statistics are kept on marijuana poisonings, the nation's canine-to-pot ratio reveals potential for a problem. The American Pet Products Manufacturers Assn. estimates that 43 million U.S. households include a dog, while more than 25 million Americans fessed up on a 2003 government survey to having used marijuana at least once in the previous year.
In Northern California, which is believed to have the highest concentration of medical marijuana users in the country and where pot cultivation is a popular hobby, vets face a preponderance of such cases, with some attending to several zonked-out dogs a week.
But unlike in human medicine, where entire textbooks are dedicated to doctor-client communication, there are no such rules for vets, leaving them to their own strategies for broaching a touchy question: Any chance the dog ate your stash?
