People anxious to relieve suffering in their pets are increasingly turning to oils and powders that contain CBDs, a non-psychoactive component of marijuana.
US vet Dr Byron Maas surveys a supply of marijuana products for dogs that lines a shelf in his veterinary clinic. They're selling well.
"The 'Up and Moving' is for joints and for pain," he explains.
"The 'Calm and Quiet' is for real anxious dogs, to take away that anxiety."
But there's little data on whether they work, or if they have harmful side effects.
That's because Washington has been standing in the way of clinical trials, veterinarians and researchers say. Now, a push is underway to have barriers removed, so both pets and people can benefit.
Those barriers have had more than just a chilling effect.
When the federal Drug Enforcement Administration announced last year that even marijuana extracts with CBD and little or no THC - marijuana's intoxicating component - are an illegal Schedule 1 drug, the University of Pennsylvania halted its clinical trials. Colorado State University is pushing ahead.
The US Food and Drug Administration has warned companies that sell marijuana products online and via pet shops and animal hospitals that they're violating laws by offering "unapproved new animal drugs". The FDA threatened legal action.
But, seeing potential benefits of CBDs, the American Veterinary Medical Association's policy-making body said it wants the DEA to declassify marijuana as a Schedule 1 drug "to facilitate research opportunities for veterinary and human medical uses."