Q. Is dehorning necessary?
A. Yes. Dehorning significantly decreases the risk of injury to farm workers, horses, dogs and other cattle. Dehorned animals are far easier to handle and transport, and command higher prices at auction than animals with horns.
The American Veterinary Medical Association (AVMA) recognizes that dehorning is a necessary management practice for human and animal safety.1 The vast majority of dairy and beef farmers dehorn their animals, or raise polled animals, which are born without horns.
Q. Is dehorning painful?
A. Yes. The corneal nerve, running from behind the eye to the base of the horn, supplies sensation to the horn. Studies have shown that dehorning stimulates both an acute pain response and a delayed inflammatory reaction.2
According to Dr. Todd Duffield, a researcher at Ontario Veterinary College at the University of Guelph, “With the possible exception of caustic paste, calves perceive and react to acute pain during dehorning, regardless of method, when no local anesthetic is used.” 2
The American Veterinary Medical Association recognizes that dehorning causes pain, and recommends the use of procedures and practices, including approved medications, to eliminate or mitigate discomfort.1
Q. At what age should cattle be dehorned?
A. The American Veterinary Medical Association recommends dehorning at the earliest age practicable.1 Young calves tend to recover quicker and have fewer complications than calves dehorned at an older age. It is generally accepted that the younger the animal, the less painful the procedure is.2
Q. Besides the American Veterinary Medical Association, which other organizations recommend disbudding at a very young age?
A. Several national and international organizations and universities support early-age disbudding of cattle:
- In the United Kingdom, paste disbudding is recommended in cattle up to seven days old.3
- In Australia and New Zealand, chemical dehorning is permitted if performed within the first few days after birth.3
- Texas A&M recommends castrating and dehorning be performed at birth.5
- Researchers at the University of Tennessee recommend dehorning be performed “at less than one month of age, before the horn bud attaches to the skull, to avoid complications and set-backs.”6
Q. Why is dehorning believed to be less painful for very young calves?
A. In calves less than two months of age, horn buds are free-floating. Eventually, the buds begin to grow and attach to the skull overlying the frontal sinuses. Then the horns acquire a blood supply. Dehorning at this late stage is more invasive, causes blood loss, exposes the frontal sinus cavity and increases the risks of sinusitis, prolonged wound healing and infection.3
Q. What kind of dehorning methods are used?
A. Dehorning methods range from disbudding with caustic paste or a hot-iron when horn buds are not yet formed, to the use of saws, wires, knives and other cutting instruments for removal of already-developed horns. In a 2008 survey of northern dairy farms in the United States, about 70% use a hot-iron to disbud their calves,7 while most beef cow-calf producers use saws, Barnes or guillotine dehorners.8 Only about 10 percent of producers use caustic paste.7,8
Q. Which dehorning method is least painful?
A. All methods of horn removal are painful. However, in an article published in the Journal of Dairy Science, researchers from the University of British Columbia found that calves dehorned with caustic paste experienced less pain than calves dehorned with a hot iron, even when a nerve block was used.9 The authors concluded that, “caustic paste dehorning with xylazine sedation might be a more humane, simpler, and less invasive procedure than hot-iron dehorning with sedation and local anesthesia.”
Q. What are other ways producers can mitigate the pain of dehorning?
A. Administering a sedative prior to dehorning, such as xylazine, can help calm the animal. Injection of a local anesthetic (nerve block), like lidocaine, can control acute pain associated with horn removal. Post-operative pain relief may be obtained with non-steroidal anti-inflammatory drugs, such as ketoprofen. This combination of a sedative, local anesthetic and NSAID therapy, along with low-stress animal handling practices, can greatly reduce the calf’s pain and distress during dehorning and in the hours that follow. Producers should always consult their veterinarians before administering any injections or drug therapies.
Q. What do animal welfare groups think about dehorning?
A. While not all animal welfare groups have policies or position statements on dehorning, here are some that do. For more information, visit each organization's Web site or contact them directly.
- The American Humane Association, which administers the American Humane® Certified program, prohibits dehorning without anesthesia after four months of age.
- Mercy For Animals has no official position on dehorning per se, but MFA Director Nathan Runkle has told ABC News that cows dehorned in this undercover video were “too old” for the process.10
Q. Do horns ever grow back?
A. If the disbudding or dehorning procedure is performed correctly, horns should not grow back. However, if some horn cells remain (when a hot-iron isn’t hot enough, for example), the animal will need to be dehorned a second time.
Q. Are cattle ever born without horns?
A. Yes. The presence or absence of horns is a genetic trait, and breeding hornless or “polled” cattle is a non-invasive way to dehorn. Polled livestock are becoming common among beef cattle, but are still unusual among dairy breeds.
- American Veterinary Medical Association Animal Welfare Policy. Castration and Dehorning of Cattle. Approved April 2008.
- Duffield, Todd. Current Data on Dehorning Calves. AABP Proceedings, Vol. 41, September 2008.
- AVMA Backgrounder: Welfare Implications of the Dehorning and Disbudding of Cattle. January 28, 2010.
- Pasture Weaning Cuts Stress, say University of Missouri Researchers. Beef, May 1, 2001.
- Faries, Floron C., Jr. Immunizing Beef Calves: A Preconditioning Immunization Concept. 2000. AgriLife Extension Service at Texas A&M University.
- Hopkins, Fred M., et al. University of Tennessee. Cattle Preconditioning: Dehorning Calves. July 9, 2009.
- Fulwider, W.K., et al. Survey of Dairy Management Practices on 113 North Central and Northeastern United States Dairies. J. Dairy Sci. 2008. 91:1686-1692.
- USDA APHIS, Veterinary Services, National Animal Health Monitoring System, October 2008. Reference of Beef Cow-Calf Management Practices in the United States, 2007-2008.
- Vickers, K.J. et al. Calf Response to Caustic Paste and Hot-Iron Dehorning Using Sedation With and Without Local Anesthetic. April 2005. J. Dairy Sci. 88:1454-1459.
- ABC News – The Blotter. Dehorning: 'Standard Practice' on Dairy Farms. January 28, 2010.