Not so fast. The science isn’t there. Yet
By Kim Campbell Thornton
Andrews McMeel Syndication
We bet you know at least one person who shares his or her stash with a pet. Not to get the animal high, but to relieve anxiety, nausea or pain from cancer or another ailment. But does it really work?
That’s hard to say. Anecdotes aside, no research to date shows any benefit of marijuana for dogs or cats. Only minimal research is available on its effects in humans. That’s because federal law classifies it as a Schedule I drug with no medical usefulness. Regulatory restrictions hamper researchers’ ability to study marijuana’s potential benefits for humans or animals.
In theory, cannabinoids -- the chemical compounds found in marijuana -- carry great promise, says Robin Downing, DVM, a pain management expert and hospital director at the Downing Center for Animal Pain Management in Windsor, Colorado. Dogs and cats possess cannabinoid receptors. Think of them as the “lock” into which cannabinoid molecules fit like keys.
“These are exquisitely specific receptors that do not interact with other molecules,” Dr. Downing says. Unlike THC, cannabinoids are not involved in altered mentation, but they are credited with other actions in the nervous system, such as pain relief and relief of seizure activity.
“This is what gives us hope that medical marijuana will at some point become an important tool in the pain management toolbox,” she says.
That can’t happen, though, until the drug is better understood. Right now, little is known about dosing and delivery of medical marijuana to pets.
The idea of treating pet ailments with marijuana may give rise to the image of coming home to a dog or cat who’s chowing down on Doritos and listening to Bob Marley. The truth is, we don’t know a lot about how pets respond to marijuana because they can’t tell us how they feel.
“For animals, we have no safety data, no efficacy data and no dosing data,” Dr. Downing says.
For example, she says, humans can adjust their doses based on their response to a drug, but animals cannot.
“How do we know what they are feeling? How can we tell when they have received ‘enough’ to create whatever effect we seek for them?”
At veterinary emergency hospitals, marijuana is the number-one intoxicant for pets, especially in states such as California, Colorado and Washington, which have legalized medical and recreational marijuana. A retrospective study published in 2012 looked at cases in two Colorado veterinary hospitals from 2005 to 2010. Researchers found that the incidence of marijuana toxicosis in dogs increased fourfold over the period.
“Our numbers have been increasing for several years,” says veterinary toxicologist Tina Wismer, director of the ASPCA Animal Poison Control Center. “Many vets are able to diagnose the typical patient -- wobbly and dribbling urine -- on sight.”
Typical incidents include eating an owner’s baked goods that contain marijuana or THC-laced butter or coconut oil, eating the actual plants or inhaling smoke.
“The edibles are much more dangerous due to the concentration of THC when compared to plant material,” Dr. Wismer says.
Do pets who partake get the munchies? Usually not. Signs of toxicity include glassy eyes, incoordination, dilated pupils and vomiting, usually within an hour or less or ingestion or inhalation.
Because of marijuana’s Schedule I status, veterinarians cannot legally prescribe the drug. That doesn’t mean related products aren’t available, though. Companies sell hemp tinctures, edibles and extracts formulated for pets. While hemp and marijuana are both derived from the Cannabis sativa plant, hemp is defined as containing a concentration of no more than 0.3 percent THC.
Dr. Downing worries about variability in levels of active ingredients and lack of regulation.
“We need formal studies to determine efficacy, safety, application, optimal dosing, side effects and tolerability,” she says. “We need standardized preparations with known content of active ingredients and no contaminants. Unfortunately, we are a long way from being at a place where we can in good conscience recommend marijuana for animals.”
The secret behind
feline eye shine
Q: Why do my cat’s eyes glow in the dark? -- via Facebook
A: The ancient Egyptians had a theory about that. They believed that a cat’s eyes reflected the sun, even at night when the solar orb was out of sight. I love that inspiring theory, but modern science has given it a thumbs-down. What we do know is pretty fascinating, though.
Cats have some neat evolutionary adaptations, especially when it comes to their eyesight. They can see in conditions that are more than five times dimmer than what even the sharpest-eyed human needs to spot something in the dark.
A layer of specialized tissue called the tapetum lucidum (Latin for “bright tapestry”) is what sparks that glow. Located behind the retina (the light-sensitive tissue lining the back of the eye), it converts light into electrical impulses that then travel to the brain. The job of the tapetum lucidum is to capture all the light that doesn’t enter the retina directly and reflect it back in, so that even tiny amounts of light are processed. When light strikes your cat’s eyes in a darkened room, you see that glow, also known as "eyeshine."
The tapetum lucidum puts night-vision goggles to shame and is what makes cats such brilliant twilight hunters. Two other factors contribute to the cat’s night eyesight. One is his ability to dilate his pupils (they can become three times the size of the pupil of a human eye!). The other is his large cornea, which is the eye’s outermost lens -- that clear, curved part of the eyeball in front of the pupil. It’s easy to see why a night-roaming mouse had better beware.
Interestingly, cats with green or yellow eyes tend to have a greenish glow, while cats with blue eyes tend to have a reddish glow. -- Dr. Marty Becker
Do you have a pet question? Send it to email@example.com or visit Facebook.com/DrMartyBecker.
The nose knows?
Not about pet health
-- Conventional wisdom says that a dog’s nose should be cool and moist and that a dry nose is a sign of illness. Is your pet’s nose really a barometer of his health? Not necessarily. Veterinarians are more concerned if a dog’s nose is draining. That’s a clue that something may be wrong further inside the nose: an inhaled foreign object, for instance, or an infection. Signs such as sneezing, wheezing or pawing at the nose are better evidence of a problem than whether the nose is dry or moist.
-- Storing your pet’s dry food in the bag is the best way to keep it fresh. Putting it into a metal or plastic container with a tight-fitting lid might seem like a good idea, but those containers must be cleaned regularly to remove the oily film that develops. Once you open a bag, it’s best to use it up within six months or less, even if it has a shelf life of a year. A food with fat levels of 20 percent or higher is likely to go rancid more quickly than foods with lower levels of fat.
-- A cat with a curly coat? Meet the LaPerm, “invented” in 1982 when one kitten in a litter, born bald, began to develop a soft, curly coat, the result of a natural genetic mutation. More kittens were born with the trait, and the owner began to breed them selectively. The LaPerm’s coat comes in many different colors and patterns, including solid, tortoiseshell, tabby and calico. It can be curly or wavy, short or long. The affectionate and curious cats love people and have a reputation for being lap cats. Don’t be surprised if one wants to ride on your shoulder so he can keep tabs on everything that’s going on. -- Dr. Marty Becker, Kim Campbell Thornton and Mikkel Becker
ABOUT PET CONNECTION
Pet Connection is produced by a team of pet-care experts headed by "The Dr. Oz Show" veterinarian Dr. Marty Becker and award-winning journalist Kim Campbell Thornton. They are affiliated with Vetstreet.com and are the authors of many best-selling pet-care books. Joining them is dog trainer and behavior consultant Mikkel Becker. Dr. Becker can be found at Facebook.com/DrMartyBecker or on Twitter at DrMartyBecker. Kim Campbell Thornton is at Facebook.com/KimCampbellThornton and on Twitter at kkcthornton. Mikkel Becker is at Facebook.com/MikkelBecker and on Twitter at MikkelBecker.