Position Statements

Horn Management of Small Ruminants

May 8, 2023

Position statements issued by the CVMA are not legislative. They reflect current best management practices for animal welfare.

Position

The Canadian Veterinary Medical Association (CVMA) recognizes that horn management (removal of horn buds or horns) in small ruminants may be desirable for human and animal safety reasons. The CVMA holds that veterinarians should engage with responsible and appropriately trained animal owners or caretakers in the development of individual herd horn management protocols and procedures. If horn removal is deemed to be necessary, removal should occur before horn attachment to underlying bone (between 3 and 9 days of age: disbudding). Horn removal on small ruminants after this age (dehorning) should only be performed for medical reasons, and exclusively by a veterinarian skilled in the procedure.

Summary

  • The indication to disbud or dehorn in small ruminants is herd specific depending in part, on their housing and use.
  • When disbudding is indicated, the preferred timing to maximize animal welfare is after maternal bonding has occurred and before horn attachment to bone, or between 3-9 days of age.
  • Small ruminants subjected to disbudding or dehorning by any method should always receive peri-operative analgesia.
  • Protocols including indication for horn removal, pain control, and any sedation or anesthesia, and procedures for disbudding small ruminants should be developed with and reviewed by the herd or flock veterinarian.
  • There is a lack of and a need for additional on-label approved products for small ruminant species.
  • Dehorning of mature small ruminants should only be performed by a veterinarian skilled in the procedure and only when medically necessary. It has many surgical and medication-associated risks and considerations and should only be performed after consultation with the client about the risks.
  • Procedures such as cryosurgery, caustic paste and clove oil should not be used.
  • Any significant bleeding during dehorning must be controlled (please refer to the position statement on surgical procedures).

Background

  1. In small ruminants, the indication to disbud or dehorn is situational and dependent on factors such as stocking density and risk of horn entrapment (e.g., during milking), as well as breed and purpose. Meat and fibre small ruminants are much less likely to be disbudded than dairy small ruminants. Horn management decisions for the individual herd should be undertaken in consultation with the herd veterinarian.
  2. Horns begin as buds of germinal epithelium that can be palpated on the front dorsal aspect of the skull by a few days of age. The horn buds become attached to the bone overlying the frontal sinus within a few days of life depending on breed type. As the horns grow, a diverticulum of the frontal sinus extends into the base of the horn.
  3. Both horn buds and horns are fully innervated with a good blood supply. Disbudding involves destroying the horn bud without bone damage. Dehorning involves removal of the horn, including the germinal epithelium from which the horn grows; the frontal sinus is most often opened with this procedure. Dehorning is more invasive and painful than disbudding. Tissue damage from disbudding or dehorning causes physiological and behavioral changes indicative of pain and distress (1).
  4. The polled condition in goats is genetically linked to an intersex condition and so breeding for the polled trait can not currently be done successfully in this species (2). Where horn management is indicated, disbudding is the method of choice (3) as it results in less pain and distress and reduces the risk of sinusitis, bleeding, and infection than dehorning (4).
  5. Herd veterinarians should engage in meaningful conversation and education with responsible animal owners and caretakers to develop specific horn management protocols that include the indication for the procedure, acceptable techniques, and indicated medication for pain and stress management. As horn management is a surgical procedure, the provisions of the CVMA position statement on surgical procedures (5) are applicable.
  6. Hot iron disbudding in kids may result in damage to deep tissues including the skull and brain (4) through prolonged or excessive application of heat and pressure. However, it is currently the best and most reliable method in small ruminants for disbudding (6). Methods that should not be used include cryosurgery, caustic paste and clove oil because of increased risk of scur (abnormally growing pieces of horn) formation and higher levels of pain than hot iron cautery (6). Scurs can be easily damaged, leading to chronic pain and infection.
  7. Disbudding should be done after maternal bonding but before bud attachment to the skull at approximately 3-9 days of age to reduce poor technique, scur formation and excessive pain associated with the need to apply the hot iron longer than necessary. Removal of the horn bud cap will assist in preventing scurs.
  8. Small ruminants must receive peri-operative analgesia for horn management. Sedation or general anaesthesia may be indicated by the herd veterinarian in the specific herd horn management protocol. (7). Local anesthesia technique alone in small ruminants is discouraged as it may not provide sufficient pain relief due to pain and stress associated with the procedure and the difficulty in accurately blocking the bud or horn nerve supply in these species. (7). Given their sensitivity to the medications, care must be taken in correctly dosing local anesthetics and sedatives in small ruminants for horn management. In larger farm settings, general anesthesia performed by a veterinarian may be an option.
  9. The CVMA endorses the concept that veterinarians should have advance input through a provincially defined and mandated Veterinarian-Client-Patient-Relationship (VCPR) when disbudding is performed by persons other than members of an experienced veterinary service (e.g., by livestock producing clients). Medications used for sedation of neonatal kids may be dispensed to trained animal owners or caretakers by prescription from the herd veterinarian, noting that no drugs currently available for use for analgesia, sedation and general anesthesia are licensed for use in small ruminants and are only available by prescription from a veterinarian with a valid VCPR with the client owner. There is a need for appropriate approved on-label medications for use in small ruminants.
  10. Dehorning of mature small ruminants is very painful and more prone to post-operative complications. It should be done only when medically necessary. It has many surgical risks and medication considerations and should only be performed by a veterinarian skilled in and comfortable with the procedure, and after consultation with the client about the significant risks. In some situations, horns may be trimmed instead of removed.

References

  1. Baker J.S. Dehorning small ruminants. Bovine Practice 1981;2(1):33–34,36–39.
  2. Pailhoux E, Vigier B, Vaiman D, Servel N, Chaffaux S, Cribiu EP, Cotinot C. Otnotgenesis of female to male sex-reversal in XX polled small ruminants. Developmental Dynamics 2002, March 26. https://anatomypubs.onlinelibrary.wiley.com/doi/10.1002/dvdy.10083
  3. Alvarez L, Adcock SJJ, Tucker CB. Sensitivity and wound healing after hot iron disbudding in goat kids. J Dairy Sci. 2018 102:10152-10162 https://www.journalofdairyscience.org/article/S0022-0302(19)30741-6/fulltext
  4. Hempstead MN, Shearer JK, Sutherland MA, Fowler JL, Smith JS, Smith JD, Lindquist TM, Plummer PJ. Cautery Disbudding Iron Application Time and Brain Injury in Goat Kids: A Pilot Study. Front. Vet. Sci., 18 January 2021. https://www.frontiersin.org/articles/10.3389/fvets.2020.568750/full
  5. Surgical Procedures Performed on Animals: CVMA Position Statement https://www.canadianveterinarians.net/policy-and-outreach/position-statements/statements/surgical-procedures-performed-on-animals/
  6. Brooks KMS, Hempstead MN, Anderson JL, Parsons RL, Sutherland MA, Plummer PJ, Millman ST. Characterization of Efficacy and Animal Safety across Four Caprine Disbudding Methodologies. Animals 2021 11(2). 430 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7915256/
  7. Hempstead MN, Lindquist TM, Shearer JK, Shearer LC, Sutherland MA, Plummer PJ. Acute cortisol and behaviour of dairy goat kids administered local anesthesia, topical anesthesia or systemic analgesia prior to cautery disbudding. Physiology and Behaviour Volume 222, 1 August, 2020. https://www.sciencedirect.com/science/article/pii/S0031938420302560?via%3Dihub