With the progressive deregulation of cannabidiol (CBD)-supplements containing low levels of the psychotropic cannabinoid tetrahydrocannabinol (THC), the market of human and pet-care products is expanding.  Many concerns by the Food and Drug Administration (FDA) are related to the lack of precise and reliable analysis and a grey zone of regulation surrounding the animal supplements area. The absence of clear guidelines for hemp-derived products allows the spread of adulterated and dubiously labelled products. For this reason a recent publication focused on the analysis of 29 veterinary food supplements with low-THC levels in order to provide infos regarding the stated content of cannabis constituents including cannabinoids, terpenes and the eventual heavy metal contamination. The analysis were performed thorugh liquid chromatography with diode array detection and mass spectroscopy (LC-DAD/MS), headspace gas chromatography (HS-GC- FID) and inductive coupled plasma mass spectroscopy (ICP- MS), respectively.  Among the analyzed cannabinoids there are CBD, THC, THC-8, cannabigerol (CBG), cannabinol (CBN), cannabichromene (CBC), tetrahydrocannabivarin (THCV), cannabidivarin (CBDV), cannabidiolic acid (CBDA), tetrahydrocannabinolic acid (THCA), and cannabigerolic acid (CBGA). The terpenes included β-myrcene, linalool, limonene, β-caryophyllene, pinenes, eucalyptol and 3-carene while the analyzed heavy metals included lead, arsenic, mercury and cadmium.  From the tests came out that only 10 of the 29 products were within the labels claims regarding cannabinoids concentrations. The discrepancies from the stated composition could be dependent on various factors such as cannabinoid conversion or degradation over time, poor formulation stability and analysis carried out with superficiality at the time the batches were released. For a correct dosage it is important to have reliable certificate of analysis reporting the actual cannabinoid and other constituents concentrations in order to ensure the product safety and efficacy. Checking the terpenic fractions, it was noticed that in some cases, products presented an unnatural amount of certain terpenes, in order to enhance the aroma or to increase the therapeutic effects of these substances in combination with cannabinoids. Because it is common practice to plant hemp for soil remediation in contaminated lands, a serious concern is linked to health issues related to the accumulation of heavy metals like lead or arsenic in plant-derived products. Four of the 29 tested veterinary products showed high concentration of heavy metals above the permitted safe limits, even if it was not possible to assess if the contamination came from the plant material, the solvent used during the product processing or the mechinery used for the extraction.  A good practice for pets owner is to always to check the certificate of analysis (COA) of the supplement of interest in order to be sure that the product is safe and free of harmful chemicals and contaminants including also microbials, mycotoxins and solvent residues in addition to heavy metals. Veterinary professionals have to evaluate the best products, asking infos to the producers about CBD and THC content for a correct posology and providing data about the pharmacokinetic and clinical application of the selected hemp-derived products.
 Wakshlag JJ, Cital S, Eaton SJ, Prussin R, Hudalla C. Cannabinoid, Terpene, and Heavy Metal Analysis of 29 Over-the-Counter Commercial Veterinary Hemp Supplements. Vet Med (Auckl). 2020;11:45-55. doi: 10.2147/VMRR.S248712. [Times cited = 38]