Cannabinoids and Animal Physiology

1) The most far-reaching of the recent advances in cannabinoid biology are the identification of two types of cannabinoid receptors (CB1 and CB2) and of anandamide, a substance naturally produced by the body that acts at the cannabinoid receptor and has effects similar to those of THC. The CB1 receptor is found primarily in the brain and mediates the psychological effects of THC. The CB2 receptor is associated with the immune system; its role remains unclear.

2) Cannabinol also lowers body temperature and increases sleep duration in mice. It is considerably less active than THC in the brain, but studies of immune cells have shown that it can modulate immune function (see “Cannabinoids and the Immune System” later in this chapter).

3) The cell responds in a variety of ways when a ligand binds to the cannabinoid receptor. The first step is the activation of G proteins, the first component of the signal transduction pathway. That leads to changes in several intracellular components—such as cyclic AMP and calcium and potassium ions—which ultimately produce the changes in cell functions. The final result of cannabinoid receptor stimulation depends on the particular type of cell, the particular ligand, and the other molecules that might be competing for receptor binding sites. Different agonists vary in binding potency, which determines the effective dose of the drug, and efficacy, which determines the maximal strength of the signal that they transmit to the cell.

4) Anandamide appears to have both central (in the brain) and peripheral (in the rest of the body) effects. The precise neuroanatomical localization of anandamide and the enzymes that synthesize it are not yet known. This information will provide essential clues to the natural role of anandamide and an understanding of the brain circuits in which it is a neurotransmitter. The importance of knowing specific brain circuits that involve anandamide (and other endogenous cannabinoid ligands) is that such circuits are the pivotal elements for regulating specific brain functions, such as mood, memory, and cognition.

5) Cannabinoids likely have a natural role in pain modulation, control of movement, and memory. The natural role of cannabinoids in immune systems is likely multi-faceted and remains unclear. The brain develops a tolerance to cannabinoids. Animal research has demonstrated the potential for dependence, but this potential is observed under a narrower range of conditions than with benzodiazepines, opiates, cocaine, or nicotine. Withdrawal symptoms can be observed in animals but appear mild compared with those of withdrawal from opiates or benzodiazepines, such as diazepam (Valium).

Reference: https://www.ncbi.nlm.nih.gov/books/NBK230721/#:~:text=Cannabinoid%20receptors%20have%20been%20studied,such%20as%20leeches%20and%20mollusks

Veterinarian Discussion of Cannabis Within the Veterinarian-Client-Patient Relationship

1) California Veterinarians- On September 27, 2018, Governor Edmund G. Brown Jr. signed into law Assembly Bill 2215 (Kalra, Chapter 819, Statutes of 2018). AB 2215 became effective January 1, 2019. This bill amends section 4883 of, and adds a section 4884 to, the BPC relating to veterinarians. The bill prohibits VMB from disciplining, or denying, revoking, or suspending the license of a licensed veterinarian solely for discussing the use of cannabis on an animal for medicinal purposes, absent negligence or incompetence.

2) Industrial Hemp: Under federal and state law, hemp is not a controlled substance regulated under the Uniform Controlled Substance Acts and is not regulated under the Medicinal and Adult-Use Cannabis Regulation and Safety Act (MAUCRSA). Rather, industrial hemp is regulated by the federal Department of Agriculture and the California Department of Food and Agriculture.

3) Documentation of discussions should include the indication and safety of the use of cannabis.

4) Conflicts of Interest: A veterinarian, registered veterinary technician (RVT), or veterinary assistant controlled substance permit (VACSP) holder may be disciplined for the offer, delivery, receipt, or acceptance of any rebate, refund, commission, preference, patronage dividend, discount, or other consideration as compensation or the inducement for referring patients, clients, or customers to a cannabis licensee.

5) The Board is authorized to discipline a veterinarian who accepts, solicits, or offers any form of remuneration from or to a cannabis licensee if the veterinarian or his or her immediate family has a financial interest with a cannabis licensee.

Reference: https://vmb.ca.gov/forms_pubs/cannabis_discussion.pdf

The Hype and Hope of Veterinary Cannabis

1. Is there research supporting that use or underlying any of the claims made for the scores of cannabis and cannabinoid-based products marketed for pets? Does a practitioner who recommends such a product for a patient risk running afoul of the state licensing board, the Food and Drug Administration, or the Drug Enforcement Administration? These were just some of the thorny issues covered during the first-ever AVMA Cannabis Symposium, held Aug. 20-22 during the AVMA Virtual Convention 2020.

2. "We certainly recognize the potential opportunities that cannabis-derived compounds may offer and acknowledge the significant interest in these possibilities,” said symposium speaker Randall Gnatt, a senior regulatory counsel in the Office of Surveillance and Compliance in the FDA’s Center for Veterinary Medicine.

3. California is the only state to specifically address veterinarians’ ability to engage with clients, indicating that veterinarians can discuss the use of cannabis for medical purposes with clients without being disciplined by the veterinary medical board solely for having that conversation. By that same statute, veterinarians are prohibited from prescribing, dispensing, or administering any cannabis or cannabis-based products.

4. “We don’t know about coadministration with other medicines or risks to vulnerable human and animal populations. This doesn’t mean that we know CBD is categorically unsafe under all circumstances, but given the gaps in our current knowledge and the known risks that have been identified, we’re not at a point where we can conclude that CBD products are safe for use.”

5. In 2019, the AAVSB surveyed state veterinary licensing boards about whether it is legal for a veterinarian to discuss cannabis with a client. Jim Penrod, executive director of the American Association of Veterinary State Boards, said the association recently contacted those boards to determine whether they were still comfortable with the answers they gave in the 2019 survey, and several changed their answers. Responses varied... Six states said veterinarians could lose their license if they even talk about cannabis; four said veterinarians need to adhere to federal law; seven said state boards can’t provide legal advice; seven said they have no formal opinion on the matter; two said veterinarians could talk about cannabis but only if the client starts the conversation; 18 responded that veterinarians could discuss cannabis but could not prescribe or dispense it; and four said veterinarians could discuss the topic.

Bonus: Dr. Hazzah, a founder and the co-president of the Veterinary Cannabis Society, cited a 2015 study that evaluated 75 edible cannabis products available in various California cities and found that just 7% of the products were accurately labeled for the cannabinoid content. In a follow-up session, Jack Henion, PhD, professor emeritus of toxicology at Cornell University, also conveyed results of a similar study where 12 of 13 animal products had greater THC levels than acceptable limits. “It is important that clients do their due diligence and ask for a certificate of analysis,” said Dr. Hazzah.

Reference: https://www.avma.org/javma-news/2020-10-01/hype-and-hope-veterinary-cannabis