You may have seen a sign in your local pet store or dispensary advertising CBD — the chemical compound in cannabis that doesn’t get you high and has shown multiple health benefits in people — for pets. Cannabis businesses are flocking to the $30 billion pet market, offering CBD dog supplements and other pot-infused wellness products for animals. As California joins seven other states in legalizing the plant for adult use, pet owners, veterinarians and dispensaries are looking at how cannabis might benefit animals.

The problem is that while physicians can recommend (but not prescribe) cannabis for their human patients, California veterinarians are legally prevented from giving pet owners advice or recommendations regarding the use of medical cannabis. While all cannabis, even CBD, is still federally illegal, pet owners can purchase and give CBD to their pets in legal states. But depending on their state rules, vets may risk losing their licenses if they broach the subject.

As with many things cannabis, when it comes to pot for pets, the rules have not caught up with the science, the business or the culture.

But what do veterinarians think about the safety and benefits of marijuana for animals?

Dr. Gary Richter, 47, a veterinarian of 20 years, is the owner and medical director of both Montclair Veterinary Hospital and Holistic Veterinary Care of Oakland. Richter has been outspoken on the topic of cannabis for pets, researching its uses for the past three years.

Richter is part of a movement among vets to change the regulations so that vets can oversee medical cannabis for animals. The movement was started largely by Dr. Doug Kramer, a Los Angeles vet who paved the way for the topic before he died in 2013.

Richter gave a presentation on cannabis for animals before the California Veterinary Medical Association in October. The issue is “at the forefront of the conversation in the veterinary world right now,” he said, as legislation will be debated over the next few months.

“While there are some differences in how cannabis affects pets compared to humans, they can benefit in many of the same ways people do,” Richter said. He adds that his professional experience “has shown me that there is enormous potential to treat medical conditions with cannabis.”

But Richter warns that while CBD is medically beneficial, THC, the chemical compound in cannabis responsible for the “high” effect, can be dangerous to animals. THC overdoses in dogs in particular lead may to medical complications and, in extreme cases, death. He believes cannabis should be given to pets only as a medicine, based on a veterinarian’s professional analysis and dosages to prevent complications.

“There is an impression that cannabis is 100 percent safe,” he said. “This is not true, especially in pets. … An overdose of cannabis can lead to loss of balance, loss of appetite and sometimes collapse. In rare cases, an overdose of cannabis can be fatal.”

Liz Hughston, a 47-year-old Registered Veterinary Tech in San Jose, and founder and head technician of VetTechXpert, is also an administrator of the Veterinary Cannabis Academy on Facebook and an advisory board member for Phyto Animal Health (a division of Medical Marijuana Inc.), which produces hemp CBD oil for pets.

She first grew interested in pot for pets after her dog reacted badly to a pharmaceutical anxiety medication her vet at the time recommended. Cannabis supplements did wonders, she said, without the side effects of the drug.

She says people are giving cannabis to dogs and cats to reduce noise phobia, anxiety and itching; control pain, especially with arthritis; lessen the severity and frequency of seizures; and treat many other conditions.

The wiring that makes cannabis effective in humans and animals is called the endocannabinoid system, a series of receptors in the human brain and throughout the body that regulate many physiological processes like pain, mood, appetite, memory and more.

“Every animal with a spinal column also has an endocannabinoid system, so it stands to reason that cannabis can help many species,” she said. “I think we’ve reached an inflection point in society now where cannabis use in humans has become much more widespread and accepted. People see the good it does in people and want to provide the same benefits to their pets.”

Robert Silver, a retired veterinarian of 35 years from Boulder, Colo., is also a veterinary herbalist and past president of the Veterinary Botanical Medical Association. He has spent years of his career advocating for the veterinarian use of hemp, and more recently cannabinoids. He consults with the hemp company Folium Biosciences as their chief veterinary officer and the veterinary nutraceutical company RxVitamins as chief medical officer.

Silver, 68, was skeptical about medical marijuana, but over the years began to see how animals benefit from cannabinoid treatments.

“As I explored the phytopharmacological aspects of this plant, I fell in love with it,” he said.

Unlike in California, Colorado vets can legally offer cannabis advice.

The Colorado Veterinary Medical Association (CVMA) states that it “recognizes the interest of companion animal owners and veterinarians regarding the potential benefits of marijuana therapies for a variety of animal medical conditions. Similar to human medicine, there is extremely limited data on the medical benefits and side effects of marijuana products in companion animals.“

After Colorado legalized marijuana in 2012, Silver observed animals undergoing cannabinoid therapies and recovering from conditions that had been hard to treat with either conventional or other integrative medicine approaches.

Silver said he has seen cancer tumors shrink and many go into complete remission with cannabis, noting that in some cases CBD will do the trick, and in others a blend of THC and CBD works best. He’s also seen dogs that have been given CBD in place of their prescribed arthritis medication “do better than on the NSAIDs.”

He’s also observed dogs with low-grade seizures who were able to stop their anticonvulsant therapies by switching to cannabis, but notes that this doesn’t happen in every case and cautions that it is always dangerous to take an animal off a prescribed seizure medication.

“This needs to be done with your veterinarian to avoid a visit to the ER,” he said.

Despite stacks of anecdotes and many animal studies (often designed to compare and assess the potential effects of cannabis for human use), Silver notes that veterinary studies of cannabis are lacking “because the DEA has put a hold on research by veterinarians making it very difficult for them to use even non-psychotropic hemp.”

Silver recommends pet owners stick to CBD and hemp to avoid the complex and potentially dangerous effects of THC in dogs and other animals, and notes that pet owners in states lacking medical marijuana laws can purchase CBD pet products online. However, anyone looking into purchasing cannabis, even for their pets, should be careful to check on their states’ laws surrounding the purchase of CBD products, and remember that even in states where cannabis is legal, CBD and other cannabis products are not federally legal.

Kat Donatello, CEO and founder of the Seattle CBD dog treat company Austin and Kat, says she gives her product to her dog, Austin, every day.

Her company started as a home kitchen project to help her aging dog Brady and young pup Austin, but it quickly became a business as demand increased.

Now her products are found online and in stores and vet clinics as well as animal rehabilitation centers in 15 states, including California. She said the vet clinics are able to carry her hemp-derived CBD product as they have reseller permits, making them technically retail establishments selling a hemp product.

“While I’m not a vet, I care very deeply for our customer’s pets,” she said. “I’m happy to work one on one to help owners find solutions to their pets’ issues. Many times we are the last resort after failed medications and other treatment options.”

The quandary keeping vets from advising their patients on pot effectively forced Dr. Tim Shu, an emergency vet of seven years in Los Angeles, out of the medical field and into the market. Frustrated with the inability to legally offer cannabis to pets after he’d witnessed the many benefits the plant could provide them, the 35-year-old quit his practice in 2015 to open his L.A. company VetCBD, which offers CBD pet supplements. He started his company “so that pet owners would have access to safe, effective cannabis products for their pets.”

He notes that for any pet owner looking for a product, formulation and dosing are the key things to watch for.

“Products should clearly state the cannabinoid contents and should be lab-tested by third-party laboratories for potency, pesticides and solvents to ensure safety and efficacy.”

Find more stories about the effects of cannabis on the body at GreenState Health.

[This story was updated to include a clarification from the CVMA, and Liz Hughston’s title.]