Supplements- A Brief Review
Equine Powders and Potions- Fact or Fable?
The list of supplements, herbal remedies, powders and potions is almost endless, tales of their unique magical powers get passed down from generation to generation and yard to yard, but which of them have actual scientific evidence to support their claims? Research into the equine is very limited but human and lab studies can add weight to our analysis, this review will briefly asses the scientific evidence of some of the more common supplements and remedies. Many of the herbal remedies are focused on systemic health, naturally in the equine many owners look to supplement for hoof health/growth as well, so a section will be focused on hoof supplementation. It is important to point out that herbs, vitamins and minerals are not the same thing, vitamins are organic substances and are essential for bodily function such as releasing energy from food, developing red blood cells, helping in blood clotting and in maintaining healthy skin, eyes, and hair. Minerals, which are non-organic are utilised in bone and tooth formation, blood coagulation and muscle contraction.
Bee pollen, as the name suggests is collected from plant sources by honey bees, used as a building material in their hive and to embalm foreign dead invaders. It is important to state that bee pollen/propolis from different Bee hives will have different chemical properties (Williams and Lamprecht 2008), but it has shown to have free-radical fighting properties (Christov et al 2004), free radicals are highly reactive molecules that can cause damage to living cells, anti-oxidant, antibacterial, antifungal, antiviral, anti-inflammatory, hepatoprotective and antitumor properties have all been proven in human research and many off these benefits can be derived from honey too (Gomez-Caravaca et al 2006).
Research specific to the equine, Turner et al (2006) although only a pilot study, showed that bee pollen products enabled increased feed consumption and retaining of nutrition in working horses, suggesting it could have a positive effect on performance due to helping horses meet their nutritional demands. Bee pollen has, as yet, not shown any negative side effects (Williams and Lamprecht 2008).
Devils claw is a plant, native to Southern Africa, it has been widely used in human medicine for the treatment of degenerative joint disease. There has been research to prove the anti-inflammatory and analgesic properties of Devils claw (Braun and Cohen 2015), some of this has been attributed to its additional anti-oxidant properties (Grant et al 2009), administration of Devils claw has shown to be vitally important in its efficacy as stomach acid was shown to render the remedy ineffective in some cases (Soulimani et al 1994). Chondroprotective properties have also been shown and clinical applications include treatment of musculoskeletal inflammatory pathologies (Mcgregor et al 2005), arthritis, back pain and oncology (Braun and Cohen 2015).
The research appertaining to the equine, Pearson et al (2015), again a pilot study, showed the potential beneficial effects of a mixture of herbs : dandelion, devil’s claw, stinging nettle, burdock, and comfrey on joint disease within the horse, it was shown to supress the levels of prostaglandin e2 which has been shown to be associated with pain in arthritic conditions (May et al 1994), however no reduction in lameness was observed. The possible negative effects of Devils claw could include gastric ulcers (Izzo et al 2005) however appertaining to the equine, Harman (2002) found no evidence of adverse effects.
Echinacea is a flower extract from eastern and central north America. Most research has concentrated on its modulatory influence on immunity systems, but is has also shown antiviral, antifungal, antimicrobial, anti-inflammatory, antitumor, antioxidant, mosquitocidal, and psychoactive properties, amongst other properties (Billah et al 2019). Echinacea use in the treatment of upper-respiratory infections has shown positive results (Drisko and Kindcher 2016), Parsons et al (2018) outlined the potentiality of the herb stating that advances in technology and research into the different strands of extract could yield more benefits over and above the anti-inflammatory, anxiolytic (anxiety reduction) and antibiotic properties already proven.
In the horse, O’Neill et al (2010) confirmed the herbs stimulation of equine immunocompetence, increasing the abilities of white blood cells and increasing the amount of red blood cells, haemoglobin and packed cell volume which would point to additional performance enhancing properties. Potential side effects have been shown such as allergic rashes, hyper eosinophilia, and autoimmune diseases and leukopenia with Echinacea overusage or with overdosage (Barrat 2003).
Flaxseed/Linseed, as the names suggest are crop seeds, it is rich in omega-3 fats, protein and fibre. It has been shown to have anti-oxidant, anti-diabetic, anti-cancerous properties and aid in osseous metabolic moderation, however negative effects are a potential depending on dosage and preparation (Soni et al 2016). Gutte et al (2015) expressed the potential treatment benefits to a range of diseases including cardiovascular diseases, diabetes, hypertension and neurological disorders. The benefits of omega-3 fatty acids are well known, anti-inflammatory properties have been documented (Calder 2015), and studies have shown the importance of correct balance between omega-6 and omega-3 fatty acids in the control of obesity (Simopoulos 2016), providing this balance coupled with the anti-inflammatory properties could be a mechanism for aiding the control of systemic, chronic, inflammatory processes in the equine, such as equine metabolic syndrome and laminitis, however the results were inconclusive in Hansen et al (2008) which administered flaxseed to healthy horses, questioning whether flaxseed contained high levels of omega-6 as well, studies have shown that there are potentially better sources of omega-3 fatty acids, most markedly in marine oils (Hess et al 2012). Flaxseed has shown to reduce allergic skin reactions in the equine, however with an unknown mechanism in O’Neill et al (2002), this study also expressed the different outcomes of flaxseed according to administration methods. Flaxseed has the potential negative effects of the prolonged absorption of other drugs and prolonged bleeding time, also possible cyanide poisoning in some cases if not boiled (Williams and Lamprecht 2008).
Ginseng is one of the widest used herbal supplements on the equine market and human research is widespread, it comes from the root of the plant genus Panax. Properties of ginseng are said to possess antioxidant properties that provide immunological and neurological protection. In human qualitative studies it has shown to be effective in the treatment of dementia, chronic obstructive pulmonary disease, and heart failure, however the results were questionable due to bias (Davis and Behm 2019), other studies have shown it may have benefits in appetite suppression, however Ginseng from different geographical areas were shown to have differing and even opposing effects, so more research is needed to outline its benefits (Zhang et al 2017). Compound K found in ginsenosides has shown potential in the treatment of Alzheimer's disease and cerebral ischemia, more research is needed to establish all of the potential benefits and preventions of neurological disease (Oh and Kim 2016). There have been findings of toxic hepatitis and acute kidney dysfunction associated with ginseng, however this wasn’t ginseng in isolation and could prove to be circumstantial (Lee et al 2017).
Pearson et al (2007) found benefits to the equine with no adverse effects, a low dosage showed to increase the antibody activation in response to viral infection, discussed was the need for further research into the individual ginsenosides found in ginseng to establish their individual benefits. Their interactions with non-steroidal anti-inflammatory drugs has to be considered as this has shown to have potentially adverse effects (Poppenga 2001).
Garlic has been understood as having beneficial properties since the ancient civilisations of India, China and Greece, it is widely used in the poultry industry for its anti-microbial and anti-parasitic properties (Williams and Lamprecht 2008), however Buono et al (2019) bought into question the parasitic effects of garlic in the equine showing that it had little effect on the internal egg count. It has been shown to have anti-oxidant and anti-cancerogenic properties, also having positive effects on the regulation of internal apoptotic pathways, apoptosis being the organised process of cell death, anti-viral properties have also been researched (Chmelikova et al 2017). Commonly it is used for its fly repellent properties in the equine, the mechanism for this is only expectant and is attributed to the assistance of disintegration of mucous (Elghandour et al 2018), garlic has however shown to be beneficial in equine respiratory issues and lung infections (Pearson 2004). Garlic should be fed in moderation as overdose could result in anaemic dysfunction in the equine (Pearson et al 2005), further research is needed to establish safe dosage, Williams and Lamprecht (2008) also discussed other possible side effects including gastric irritation and a lowered sperm count.
Ginger is a flowering plant, its medicinal properties come from its roots and are widely documented, Kaur et al (2015) emphasised its role in the treatment of gastric pathologies including, ulcers, vomiting, nausea, dyspepsia, stomach ache, spasm, and gastrointestinal cancer, ginger has also shown to have benefits in treating cardiovascular disease, attributed to its anti-inflammatory, anti-hyperilidemia, anti-platelet aggregation and an