Cautery Disbudding Iron Application Time and Brain Injury in Goat Kids: A Pilot Study

Abstract

Cautery disbudding is a painful procedure performed on goat kids to prevent horn growth that may result in brain injury. Thermal damage to the cerebral cortex of the brain and subsequent neurologic disease is a primary concern. Cautery iron application time may affect transmission of heat to the brain; however, research in this area is scarce. Therefore, the objective of this pilot study was to evaluate the effect of iron application time on brain injury of goat kids. A total of six buck and doe kids <9 days of age were obtained from a commercial dairy and transported to an Iowa State University research facility. Kids received a different randomly assigned application time (5, 10, 15, or 20s) on each horn bud. Kids were disbudded using an electric cautery iron (under isoflurane general anesthesia). After a 5-day observation period, the kids were euthanized, and magnetic resonance (MR) images were acquired to evaluate brain injury. Additionally, four of the six kids were presented for gross examination and two kids were selected for histopathologic examination. From the MR images, white matter edema was observed subjacent to four treated areas, representing application times of 5 s (one horn bud), 15 s (one horn bud), and 20 s (two horn buds). With the exception of the horn bud that received 5 s, which had white matter edema restricted to a single gyrus, the remaining three groups had a branching region of edema. No bone abnormalities were identified on any kids. Gross evidence of discoloration and hemorrhage on the cerebral hemispheres was observed on two horn buds that received 20 s, two horn buds that received 15 s, and one horn bud that received 10 s. Microscopic lesions consisting of leptomeningeal and cerebrocortical necrosis were observed in sections of brain from all groups. Lesions were most severe with 20 s. In conclusion, all application times used in this study resulted in some level of brain injury; however, using 15 s or more resulted in more severe and consistent brain injury. These results indicate that extended iron application time may increase the risk of brain injury in cautery disbudded kids.

Health and Welfare Survey of 30 Dairy Goat Farms in the Midwestern United States

“…Seventy percent of producers used the cautery iron for 8 s or more to disbud their kids, which may increase the risk of thermal injury to the brain. In a recent pilot study by our group on the effect of cautery iron application duration on brain injury in goat kids (by a trained and experienced operator), we observed brain injury in at least some goat kids at all duration applications (5, 10, 15, and 20 s); however, longer applications resulted in more severe and consistent brain injury [54]. Application times of 15 and 20 s should be avoided as these durations resulted in severe histopathological changes, including a branching region of edema across multiple gyri, hemorrhage, and microscopic lesions consisting of leptomeningeal and cerebrocortical necrosis [54].…”

“…In a recent pilot study by our group on the effect of cautery iron application duration on brain injury in goat kids (by a trained and experienced operator), we observed brain injury in at least some goat kids at all duration applications (5, 10, 15, and 20 s); however, longer applications resulted in more severe and consistent brain injury [54]. Application times of 15 and 20 s should be avoided as these durations resulted in severe histopathological changes, including a branching region of edema across multiple gyri, hemorrhage, and microscopic lesions consisting of leptomeningeal and cerebrocortical necrosis [54]. Cautery disbudding training should be included as part of routine training programs for farm staff by a veterinary practitioner or an experienced operator.…”

Welfare Assessment of 30 Dairy Goat Farms in the Midwestern United States

“…Together, these results demonstrate firstly, the difficulty in preventing horn regrowth in goats, and secondly, deficiencies in adequate training and practice of the operators performing disbudding, which is an area gaining attention for dairy calves (54,55), but is still required for the dairy goat industry. In addition, extended iron application can cause brain injury in goat kids (56), which may mean that disbudding operators use less application time than required to adequately destroy the horn buds to avoid brain damage. Therefore, alternatives to cautery disbudding that reduce or eliminate pain and brain injury should be investigated.…”

Pain Mitigation Strategies for Disbudding in Goat Kids

“…Surviving goat kids display signs of incoordination, paraplegia, and convulsions even up to 3 weeks. The application time is also crucial, as the placement of a cautery iron for 15 to 20 s has been shown to cause severe brain injuries [21].…”