Cannabis has been used medicinally for centuries. In fact, the use of cannabis for medicinal purposes can be traced back to ancient civilizations in China, the Netherlands, and Greece, among others. However, only recently have scientists began to document its effectiveness.
Currently, there are over 13,000 journal articles on cannabinoids and more than 1,500 on cannabidiol (CBD) specifically (US National Library of Medicine and National Institutes of Health). These articles range from rigorously critiqued peer-reviewed journal articles to scientific studies conducted by private companies. And the evidence for cannabinoids’ efficacy in a variety of applications, including animal models, is astounding.
A survey article published by Trends in Pharmacological Sciences summarized 76 scientific reports from 1980-2009 and highlighted the pharmacological applications of non-psychotropic cannabinoids. These include cannabinoids as a(n):
As you can see, the potential for these phytochemicals is tremendous for both humans and animals.
Is CBD Safe?
First, to the question that is of primary concern: Is CBD safe? According to an extensive review in 2011 that looked for evidence that CBD could have harmful effects, the answer is yes, CBD is safe. And by “safe” we are referring to the fact that this report found CBD to be non-toxic with very few, if any, side effects (US National Library of Medicine and National Institutes of Health).
As for the potential addictive properties of cannabis, it is important to differentiate THC from CBD. Marijuana, which is mildly addictive, has high levels of THC. Hemp, on the other hand, has low THC and high CBD, and is neither mentally nor physically addictive. In fact, study after study has shown that CBD actually has anti-addictive properties and can be beneficial in treating addictions to alcohol, tobacco, opiates, and psychostimulants in people and animals (Journal of Neuroscience).
In addition to addiction, the list of conditions that CBD seems to help is expanding everyday. While there are always opportunities for new research, current peer-reviewed journal articles provide great insight into the relationship between CBD and pet health.
Separation from their owner or home, noise from thunder or fireworks, and fear of strange people or situations are all common sources of anxiety in pets. Just like anxiety in humans, anxiety in pets can be disruptive. Therefore, it is important to recognize if your pet suffers from anxiety and if so, in what situations.
Areas of the brain involved in mood, stress, and fear are rich in cannabinoid receptors called CB1 receptors. These receptors help mediate fearfulness and anxiety. If these CB1 receptors are blocked or deficient, it can cause people or animals to become constantly fearful or anxious. Cannabinoids help by creating a calming (or anxiolytic) effect by boosting these CB1 receptors in our brains.
Many studies have shown that CBD has similar effects on anxiety as approved drugs often administered by veterinarians and doctors to treat anxiety. A 2014 review by the Brazilian Journal of Medical and Biological Research concluded that “the anxiolytic and antipsychotic properties of CBD stand out. CBD’s anxiolytic effects are apparently similar to those of approved drugs to treat anxiety.”
Aging and Mental Function
Just like people, pets suffer from the loss of mental abilities with age. In humans, we call this reduced brain functioning Alzheimer’s disease. In animals, this is called Cognitive Dysfunction Syndrome. People and animals with these conditions exhibit dramatically reduced functioning of cannabinoid receptors in the brain as well as increased plaque deposits and microglia, which cause inflammation.
As mentioned above, cannabinoids have neuroprotective, anti-inflammatory, and antioxidant properties that could be important in protecting nerve cells. One experiment showed that when rats injected with substances that correlate with plaque formation are also given cannabinoids, they perform better in tests of mental ability than those not receiving cannabinoids. After analyzing their brains, they saw that cannabinoids prevented the activation of microglia, resulting in reduced inflammation and preservation of mental function (The Journal of Neuroscience).
New research also suggests that CBD helps regenerate new neurons in the part of the brain responsible for memory. Researchers found that when CBD is administered to animals with memory loss, their memory improves (Journal of Neurochemistry).
One of the most prevalent conditions that affects cat and dog health is arthritis. Pets can suffer from both osteoarthritis (the kind associated with age) and rheumatoid arthritis (the kind associated with autoimmune disease). CBD can decrease the symptoms of both types of arthritis by acting as both an immunosuppressant and anti-inflammatory, protecting joints against severe damage and inhibiting the release of the tumor necrosis factor that causes joint inflammation and destruction (National Academy of Sciences, US).
An autoimmune disorder occurs when the body’s immune system attacks normal cells in the body as though they were invaders. It typically targets cells in the thyroid, blood, joints, eye, skin, and even some internal organs.
Unfortunately, dogs are prone to several autoimmune disorders including:
Immune-mediated hemolytic anemia and/or thrombocytopenia
Retinal degeneration syndrome
Because cannabinoids affect almost every component of the immune system, researchers have dedicated a lot of resources towards investigating their role in preventing autoimmune disease. It is widely believed that inflammation may set off an immune response, which then either misidentifies the target or fails to turn off. Therefore, because cannabinoids decrease inflammation, they may be the first step in preventing autoimmune disease in animals (The Journal of Biological Chemistry).
Like people, pets can suffer from broken bones and bone loss, or osteoporosis, with age. CBD can significantly help to prevent osteoporosis and heal fractures. Cannabinoid receptors called CB2 receptors are found throughout the skeletal system. These receptors help stimulate bone formation and inhibit bone loss.
In fact, one study showed that CBD prevented bone loss in aged rodents and promoted healing after fractures, with bones in treated animals being 35-50% stronger than those in untreated animals (Journal of Bone and Mineral Research).
According to a review by the National Cancer Institute, there is mounting evidence that cannabinoids not only help manage the symptoms of cancer and its treatment, such as pain, nausea, and fatigue, but also contain preventative properties that:
Induce cancer cells to die
Slow cancer growth
Inhibit the formation of blood vessels that feed tumors
Protect non-cancer cells
The use of cannabinoids to treat cancer dates back to 1998 when it was shown that cannabinoids induced cell death in glioma cells that form to create a very aggressive form of brain cancer. Since then, study after study has shown that cannabinoids inhibit cancer cell growth, induce cancer cells to die, and inhibit cancer cell invasion and metastasis (Journal of Pharmacology and Experimental Therapeutics).
Also, unlike traditional chemotherapies, they do this without hurting normal cells. In fact, they may even protect them and if taken along with chemotherapy, CBD can actually increase the effectiveness of the chemo drugs.
However, cannabinoids aren’t only suggested for treating cancer. There is also evidence that they may reduce the risk of developing cancer because of their anti-inflammatory effects. A 2005 report in Mini-Reviews in Medicinal Chemistry even states that cannabinoids “may represent a new class of anti-cancer drugs that retard cancer growth, inhibit angiogenesis, and the metastatic spreading of cancer cells.”
Both humans and pets suffer from a range of gastrointestinal disorders. However, inflammatory bowel disease (IBD) is particularly common and resistant to therapy. Several studies have shown that cannabis is beneficial in many gastrointestinal diseases, including IBD (European Review for Medical and Pharmacological Sciences). Because cannabinoids reduce gastrointestinal mobility and inflammation, they have been heralded as a new therapeutic strategy to treat IBD.
Degenerative myelopathy (DM) is the canine counterpart to ALS, better known as Lou Gehrig’s disease, in humans. Unfortunately, DM is a widespread occurrence amongst dogs and the condition is debilitating. Cannabis has shown tremendous effects in treating ALS. Therefore, because of the similarities in the diseases, cannabis may offer new hope in treating or preventing DM in pets.
An experiment was performed in which mice bred to develop ALS were given cannabis. Researchers saw that the disease was delayed and when it did appear, it progressed more slowly than those mice not given cannabis. As a result, the researchers concluded that “Based on the currently available scientific data, it is reasonable to think that cannabis might significantly slow the progression of ALS, potentially extending life expectancy and substantially reducing the overall burden of the disease (American Journal of Hospice and Palliative Care)”
DNA testing has identified many at-risk dogs for DM. Therefore, it only seems reasonable to attempt to slow or prevent the disease progression with cannabis.
Dogs and cats are both highly susceptible to diabetes. Unfortunately, the condition is difficult to control and many people have trouble coping with the demands of treating a diabetic pet. Cannabinoids may offer help.
Because cannabinoids have strict control over hormones and other neurotransmitters involved in homeostasis, it is no surprise that they have a great influence over metabolism. Interestingly, human cannabis users are more likely to have a lower body mass index, lower fasting insulin, and lower insulin resistance compared to non-users (Obesity, Silver Spring M.d).
Chronic inflammation plays a significant role in the development of type 2 diabetes. Therefore, the anti-inflammatory properties in CBD may lessen inflammation and reduce the chance of developing diabetes. Some studies have shown that CBD seemed to reduce the incidence in diabetes in normal-weight mice (Autoimmunity) as well as actually suppress and even reverse the disease (Diabetes.co.uk).
Free radicals occur when cell molecules have an unpaired electron, causing them to be unstable and to capture an additional electron from adjacent molecules. If they succeed, that molecule becomes a “free radical”, and the process continues until they disrupt the cell they make up.
Aging, along with environmental factors such as pollution, radiation, herbicides, and cigarette smoke increase free radical damage. Although our bodies normally produce antioxidants that neutralize free radicals, if they become to abundant, free radicals can result in cell damage.
Because CBD acts as an antioxidant, it may be helpful in preventing or treating a number of conditions that are worsened by or arise because of free radicals. The U.S. government actually holds a patent for using cannabinoids as antioxidants and neuroprotectants.
Glaucoma is a condition that consists of increased pressure within the eye that can cause pain and blindness. It is a huge deterrent to pet health and is especially prevalent in dogs. While cannabis is widely known for alleviating glaucoma to some degree, THC is the component that is most associated with this relief.
However, a recent study in cats found another cannabinoid (CBG), is equally effective and does not have THC’s mind-altering properties (Journal of Ocular Pharmacology and Therapeutics).
All major cannabinoids, including CBD, have been shown to have provide an effective defense against many bacteria, most notably methicillin-resistant Staphylococcus aureus, better known as MRSA (Journal of Natural Products). MRSA occurs in pets just as it does in people. If you have seen firsthand the damaging effects of MRSA in humans, you understand the pain and suffering that pets with MRSA must go through.
Dogs and other pets can suffer from a wide variety of inflammatory diseases including:
Inflammatory bowel disease
Masticatory muscle myositis
After years of research, many physicians and researchers have come to believe that the role of inflammation in the creation and proliferation of disease is far greater than we may have previously thought. David Agus, M.D., Professor of Medicine and Engineering at the University of Southern California and author of The End of Illness: A Short Guide to a Long Life, even states: “Inflammation is the root of cancer, hearth disease, and brain decline.”
Tanya Edwards, M.D., the founder and former Medical Director of Cleveland Clinic’s Center for Integrative Medicine, piggybacks off of that stating that inflammation is now recognized as the underlying basis for a significant number of diseases. She writes that Alzheimer’s disease, cardiovascular disease, and diabetes may all be related to chronic inflammation in the human body (Alternative Therapies, 2005). And inflammation isn’t just limited to humans. Research has shown that inflammation plays a role in activating genes that predispose an animal to certain diseases, including cancer.
Luckily, cannabinoids have shown to be very effective in suppressing inflammation all over the body by suppressing inflammatory responses and, as a result, lessening disease symptoms. They also protect against autoimmune disorders and may be helpful in preventing certain types of cancers triggered by chronic inflammation.
It comes as no surprise that obesity is at epidemic proportions among both pets and people. However, it may be surprising to some that people who use cannabis are documented to have lower prevalence of obesity, with lower BMI and a smaller waist size compared to non-users even though THC is well-known for increasing appetite (Obesity 2). While there is much more rigorous research to be conducted, this effect is hypothesized to be due to the combined actions of several cannabinoids, especially CBD and THCV.
Obsessive Compulsive Disorder (OCD)
OCD is a debilitating condition that occurs in animals as well as people. A genetic basis for the disease has even been found in some dog breeds. This condition can be especially harmful for animals as it may involve self-mutilation or chronic repetitive behavior at the cost of interacting with family or even eating.
Anecdotal reports form people with OCD support the finding that CBD reduces obsessive-compulsive behaviors and studies have shown that even at low doses, CBD has shown to decrease repetitive behavior in rats (Fundamental and Clinical Pharmacology).
Cannabinoids provide pain relief for dogs and cats in three primary ways:
Through CBD1 receptors in parts of the brain responsible for pain reception
Through CBD2 receptors in peripheral nerve endings
By causing other cells to reduce their release of inflammatory agents
Several cannabinoids, including CBD, have been used to prevent neuropathy in animals exposed to chemotherapy drugs (The Journal of Neuroscience) and can be as effective as morphine in the reduction of tumor pain (Behavioural Pharmacology). Because of their pain alleviating properties, cannabinoids have been used to treat bone cancer, which is one of the more painful tumors seen in pets (British Journal of Pharmacology).
Medical marijuana has been used for centuries in the treatment of intractable, or uncontrolled, seizures. Decades of research have shown that cannabinoids, including CBD and CBDV effectively control seizures in animal models (British Journal of Pharmacology). CBD works additively and sometimes synergistically with commonly prescribed anti-epileptic drugs (Seizure).
Unfortunately, seizures also occur in pets and are very common for some dog breeds. Many of these cases result in euthanasia. However, anecdotal reports and user surveys confirm that cannabinoids can dramatically reduce seizure rates and intensity in dogs, but no published studies are currently available.
Skin Conditions in Dogs
Recent studies have found that cannabinoids applied directly to the skin can significantly reduce itching in humans (Hautarzt) and can even protect against contact dermatitis. One study, which focused specifically on cannabinoid receptors in dog skin concluded that the compounds found in cannabinoids protect against effects of allergic inflammatory disorders and that the endocannabinoid system could be a target for treatment of inflammatory disorders such as allergic skin diseases in dogs (American Journal of Veterinary Research).
Just like people, pets can suffer from painful spinal injuries from accidents. In fact, many dog breeds are predisposed to spinal injury from intervertebral disc disease. Although research regarding CBD’s effect on recovery from spinal injury is fairly new, researches have already found that rates treated with CBD following spinal cord injury have improved movement (Neurotoxicity Research).
Not only does vomiting make your pet feel lousy, but it can also lead to dehydration and weight loss. Fortunately, cannabinoids have been shown to have anti-vomiting effects. Although most of the research has involved THC and synthetic cannabinoids, CBD has proved to work in animal models (PloS One). In fact, the cannabinoid CBDA may be even more effective than CBD in reducing nausea and vomiting in animals (British Journal of Pharmacology).
Cannabinoids and Wellness
After going through the research it is obvious that cannabinoids are on track towards becoming vital tools in the fight against disease. However, even more importantly is their value in maintaining dog and cat health, especially in middle-aged and senior pets.
Thanks to modern advances in nutrition, medication, and therapies, pets are now living longer than ever. However, this often means that they are living longer with various health issues. Cannabinoids have been shown to prevent and combat common complaints among dog and cat owners about aging including weakening mental capacities, anxiety, lack of appetite, and inflammation and pain associated with arthritis.
But beyond the potential applications to disease, cannabinoids may simply make pets feel better by improving their comfort, mood, activity, and appetite. They can help your furry friend feel and act like a younger version of themselves! In turn, this can lead to improved mental clarity, better muscle tone, and healthier nutrition – all which contribute to a longer, quality life.