Welfare Implications of Deer Velvet

Literature Review

June 29, 2009
This peer-reviewed summary has been prepared by the American Veterinary Medical Association Animal Welfare Division. While principally a review of the scientific literature, it may also include information gleaned from proprietary data, legislative and regulatory review, market conditions, and scholarly ethical assessments. It is provided as information and its contents should not be construed as official AVMA policy. Mention of trade names, products, commercial practices or organizations does not imply endorsement by the American Veterinary Medical Association.

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The issue

Velvet refers to the entire cartilaginous antler (prior to calcification) of a range of cervids including deer1 and elk.2,3,4 Most velvet antler is exported to Asian markets5 (particularly Korea) as a complementary medicine or dietary supplement, but it is also sold for these purposes in the United States. 6,5
 
Antlers in velvet are sometimes taken as trophies or eaten,7 but velvet is consumed primarily with the goal of improving or maintaining health. Immature antler contains a complex combination of proteins, amino acids, minerals and lipids.8 Benefits claimed to be derived from velvet antler include improvements in sexual function,8 immune function, athletic performance, recovery from illness and injury, and response to stress, as well as 'application[s] against cancer'9. Velvet is also commonly described as a general tonic.5 Data from empirical research are limited and there are some potential obstacles to conducting research trials on what are currently unconventional health products.10
 
Controlled trials using non-human animal subjects—Controlled trials with rats indicate velvet antler is non-toxic11,12 and may assist liver function.11 Data from research using mice indicate that velvet antler might assist in the management of adverse reactions to morphine.13 Mikler et al4 found that elk antler extract applied topically improved cutaneous wound healing in diabetic rats. One study found it improved the gait of dogs suffering from osteoarthtosis.2 Recently one author found chronic wasting disease (CWD) prions in the velvet of elk that were affected with the disease.14 CWD is a contagious, fatal prion disease of deer and elk.14 This research suggests that humans who consume antler velvet as a nutritional supplement are at risk for exposure to prions.
 

Controlled trials using humans subjects—One small-scale study found that deer velvet powder produced improvements in strength and endurance in male physical education students (n=17).1 This is balanced by results from several other studies where velvet antler did not improve muscular performance or reduce post-training pain,3,15 and failed to reduce rheumatoid arthritis symptoms not fully controlled by medication.16 The most recent meta-analysis found that chondroitin, a key component of velvet antler-based products, does not reduce joint pain caused by osteoarthritis.17

Velvet removal

Pain—Velvet antler is innervated and vascularized tissue and its removal without analgesia causes pain.18 Administration of lidocaine has been shown to be a reliable and effective form of analgesia,18,19,20,21 although there is concern that lidocaine may leave residues in the velvet antler product.18
 
The use of compression bands alone has produced mixed results.19,20 In a study where deer when anaesthetized and responses to compression, lidocaine, and no analgesia compared; animals that received a lidocaine ring block had a lower heart rate at time of removal than they did prior to treatment.20 These animals also had significantly lower blood pressure at antler removal than the compression band animals.20 In the same group of animals as the previous study, electroence-phalographic responses were evaluated between the groups.19 While median frequency and spectral edge frequency in the lidocaine ring block group were significantly lower than baseline at antler removal, they were significantly higher than baseline in compression and no analgesia groups at antler removal.20 A recent study again compared the analgesic effects of the compression ring to that of lignocaine ring blocks. This study found that the application of rubber rings by either standard procedure or a cable-tie method produced similar outcomes to lignocaine ring blocks in terms of desensitization of the antler in response to the nick test.21 However, the study also concluded that as the mechanical compression of nerves and anoxia from the occlusion of blood vessels is the most likely path of analgesic effects of compression rings, there is a much slower onset of analgesia.21 Therefore, they found that the recommendation that a delay of one hour between application of the rubber rings and removal the velvet antler is justified.21
 
Postoperative pain relief is not routinely provided when velvet antler is removed and more research is required to establish safe and effective techniques.18
 
Stress—Velvet removal and associated handling and restraint also cause physiological and psychological stress. Stress responses such as elevated plasma and salivary cortisol concentrations and body temperature may be reduced by providing sedatives and using nutritional support, including electrolytes, sugars and amino acids.22 Use of sedatives is associated with chemical residues (xylazine)23 and may produce a lighter color in the antler that is considered undesirable by some consumers (xylazine, fentazin).24
 

Acceptability

The FDA has considered applications but does not currently recognize any therapeutic effects of velvet antler. Velvet antler products, however, may be marketed as dietary supplements or nutriceuticals.

General animal welfare legislation in the United Kingdom and Ireland is interpreted as effectively banning the farming of velvet antler.25 However it is an accepted and regulated industry in other countries such as New Zealand.

Summary

Therapeutic benefits of velvet antler have not been well-demonstrated. A small amount of experimental research suggests potential use for improving joint function or wound healing; however, larger, independent trials have tended to produce negative results. The recent research finding CWD prions in elk velvet adds risk for human exposure to the disease.14 When velvet antler is farmed the removal of velvet causes stress and pain to the animal that should be mitigated through refinements of husbandry and the use of short- and long-term analgesia. The effectiveness of lidocaine as a short-term local anesthetic has been demonstrated. Further research is required to ensure drug residues are avoided, develop postoperative analgesic protocols. If compression bands are used there should be a one hour delay between placement and removal of the antler to ensure desensitization of the tissue.

REFERENCES
1. Sleivert G, Burke V, Palmer C, et al. The effects of deer antler velvet extract or powder supplementation on aerobic power, erythropoiesis, and muscular strength and endurance characteristics. Intenation J Sport Nutrition and Exercise Metabolism 2003;13:251-265.
2. Moreau M, Dupuis J, Bonneau NH, et al. Clinical evaluation of a powder of quality elk velvet antler for the treatment of osteoarthrosis in dogs. Can Vet J 2004;45:133139.
3. Syrotuik DG, MacFadyen KL, Harber VJ, et al. Effect of elk velvet antler supplementation on the hormonal response to acute and chronic exercsise in male and female rowers. Internation J Sport Nutrition and Exercise Metabolism 2005;15:366-385.
4. Mikler JR, Theoret CL, Haigh JC. Effects of topical elk velvet antler on cutaneous wound healing in strepozotocin-induced diabetic rats. J Alternative and Complementary Medicine 2004;5:835-840.
5. Herring H. Money Game. The Atlantic Monthly 2000;285:20-25.
6. Conaglen HM, Suttie JM, Conaglen JV. Effect of deer velvet on sexual function in men and their partners: a double-blind, placebo-controlled study. Archives of Sexual Behavior 2003;32:271-278.
7. Garman S. Eating horn (short note). Science 1884;3:88.
8. Tuckwell C. Velvet antler: a summary of the literature on health benefits. Australian Government Rural Industries and Development Corporation RIRDC Project No DIP-10A.
9. Kamen B, Kamen P. The Remarkable Healing Power of Velvet Antler. Nutrition Encounter: Novato CA. 2003.
10. Oberle K, Allen MN. Clinical trials with complementary therapies. Western J Nursing Research 2005;27:232-239.
11. Hemmings SJ, Song X. The effects of elk velvet antler consumption on the rat: development, behavior, toxicity and the activity of liver y-glutamyltranspeptidase. Comparative Biochemistry and Physiology 2004;C138:105-112.
12. Zhang H, Wanwimolruk S, Coville PF, et al. Toxicological evaluation of New Zealand deer velvet powder. Part 1: acute and subchronic oral toxicity studies in rats. Food Chem Tox 2000;38:985-990.
13. Kim H-S, Lim H-K. Inhibitory effects of velvet antler water extract on morphine-induced conditioned place preference and DA receptor supersensitivity in mice. J Ethnopharmacology 1999;66:25-31.
14. Angers RC, Seward TS, Napier D, et al,. Chronic wasting disease prions in elk antler velvet. Emerg Infec Dis 2009; 15(5):696-703.
15. Percival RS. Examining the effects of deer antler velvet supplementation on muscular strength, performance, and markers of delayed onset muscle soreness. Masters thesis: East Tennessee State University, 2005.
16. Allen MA, Oberle K, Grcae M, et al. A randomized clinical trial of elk velvet antler in rheumatoid arthritis. Biological Res Nursing 2008;9:254-261.
17. Reichenbach S, Sterchi R, Scherer M, et al. Meta-analysis: chondroitin for osteoarthritis of the knee or hip. Ann Intern Med 2007;146:580-590.
18. Walsh VP, Wilson PR. Chemical analgesia for velvet antler removal. New Zeal Vet J 2002;50:237-243.
19. Johnson CB, Wilson PR, Woodbury MR et al. Comparison of analgesic techniques for antler removal in halothane-anaesthetised red deer (Cervus elaphus): electroencephalographic responses. Vet Anaesthesia Analgesia 2005; 32:61-71.
20. Woodbury MR, Calukett NA, Johnson CB, and Wilson PR. Comparison of analgesic techniques for antler removal in halothane-anaesthetized red deer (Cervus elaphus): cardiovascular and somtic responses. Vet Anas Anal 2005; 32:72-82.
21. Nicol AM, Barrell GK, Gibbs SJ, Frizzell AN, and McPhee JF. Assessment of the production of analgesia induced by application of a rubber ring or local anaesthetic to the antler pedicle of yearling stags. New Zeal Vet Jour 2009; 57(3):153-159.
22. Cook NJ, Schaefer AL, Church JS. Nutritional therapy modulates stress responses of elk (Cervus elaphus Canadensis) to removal of velvet antler. Online J Vet Res 2006;10:20-25.
23. Walsh VP, Wilson PR. Sedation and chemical restraint of deer. New Zeal Vet J 2002;50:228-236.
24. Suttie JM, Haines SR, Brown-Smith AP, et al. The effect of removal technique and postremoval handling on velvet antler colour. New Zealand J Agricultural Res 2000;43:207-225.
25. Wilson PR, Stafford KJ. Welfare of farmed deer in New Zealand. 2. velvet antler removal. New Zeal Vet J 2002;50:221-227.