Wound healing and pain sensitivity following caustic paste disbudding in dairy calves

Caustic paste disbudding is increasing in popularity on commercial dairy farms in the United States, but little research has explored the pain and welfare implications beyond the acute period of this procedure. In contrast, researchers have reported it takes 7 to 9 wk, on average, for hot-iron disbudding wounds to re-epithelialize in dairy calves. Our objective was to describe wound healing and sensitivity following caustic paste disbudding. Jersey and Holstein female calves were disbudded using caustic paste (H. W. Naylor Company Inc.) at 3 d of age (n = 18), and control calves received a sham procedure (n = 15). Before disbudding, calves received a local block and a nonsteroidal anti-inflammatory drug. Calves ≥34 kg and <34 kg at birth had 0.3 or 0.25 mL of paste applied per unshaved horn bud, respectively. Following disbudding, wounds were scored 2×/wk for the presence or absence of 8 tissue categories, including the final stages: new epithelium and fully healed. Control calves were removed from the experiment after 6 wk to be hot-iron disbudded. Mechanical nociceptive threshold (MNT) measures were collected weekly to evaluate wound sensitivity until calves were removed from the study or healed. Wounds were slow to re-epithelialize (16.2 ± 5.7 wk, mean ± SD; range: 6.2-32.5 wk) and contract to be considered fully healed (18.8 ± 6 wk, mean ± SD; range: 8.7-34.1 wk). Compared with non-disbudded controls, paste calves exhibited lower MNT values for all 6 wk (mean ± SE; control: 1.46 ± 0.16; paste: 1.18 ± 0.12 N). These data indicate that wounds from caustic paste disbudding are more sensitive than undamaged tissue for at least 6 wk and take twice as long to heal compared with cautery methods described in the literature. In conclusion, caustic paste disbudding wounds took 18.8 wk to fully heal and were more sensitive than intact horn buds for 6 wk. Future work should examine whether aspects of paste application (e.g., amount used, time rubbed in, calf age, pain mitigation) could improve healing time and sensitivity.

Behavioral changes in the first 3 weeks after disbudding in dairy calves

Hot-iron disbudding, the practice of cauterizing horn bud tissue to prevent horn growth in dairy calves, results in behavioral changes indicative of pain in the first few days after the procedure. However, few studies have quantified behavioral changes in the following weeks, while the burn wounds are still healing. Female Holstein calves were disbudded with a heated iron and pain relief (5.5 mL lidocaine cornual nerve block and 1 mg/kg oral meloxicam) at 4 to 10 d of age (n = 19) or not disbudded (n = 19). Calves wore ear tag accelerometers that reported the dominant behavior being performed at 1-min intervals from 3 to 21 d after disbudding. Compared with age-matched controls, disbudded calves tended to spend more time inactive throughout the observation period, ruminated less in the first 3 to 11 d after disbudding, and sucked more from a milk bottle beginning 5 d after disbudding until the end of the 21-d observation period. In addition to the accelerometer data, live observations of sleeping (using a behavioral proxy), lying, and ruminating were collected using instantaneous sampling at 5-min intervals for 24-h periods 3, 10, and 17 d after disbudding. Disbudded calves slept with their head down more on all live observation days and spent more time lying on the 17th d after disbudding, but ruminating did not differ compared with controls, in contrast to the accelerometer results. More time spent inactive, sleeping, and lying, and less time spent ruminating (as indicated by the accelerometer) can be interpreted as attempts to reduce painful stimulation of the disbudding wounds and allocate energy to healing. It is unclear whether the greater amount of sucking in the disbudded calves is nutritive (milk present) or non-nutritive (milk absent), as the algorithm did not distinguish the type of sucking, and further research is needed to explore the factors underlying this effect. We conclude that disbudding alters daily behavior patterns for at least 3 wk, far beyond the duration of recommended pain medication, raising additional welfare concerns about the procedure.

A Clinical Trial on the Welfare Effects of Administering Meloxicam to 10 to 21 Day Dairy Calves Following Caustic Paste Disbudding

Caustic paste disbudding (CPD) is widely utilized for calves, which has been known to result in adverse effects on the calves and ethical concerns related to animal welfare, despite the use of local anesthetics. The administration of meloxicam has been demonstrated to provide benefits in alleviating pain and inflammation in juvenile calves under 9 d old and subjected to CPD. Nonetheless, there is a scarcity of literature documenting the beneficial impact of meloxicam in alleviating pain in calves aged over 9 d that have undergone CPD. Therefore, the objective of this clinical trial was to evaluate the efficacy of administering meloxicam and lidocaine for cornual nerve block together in mitigating the deleterious effects of CPD, as opposed to using lidocaine alone in calves older than 9 d. Thirty Holstein calves, aged between 10 and 21 d, were enrolled and randomly assigned to 1 of 2 treatments: lidocaine alone (Placebo), lidocaine and normal saline treatment before CPD, and lidocaine plus meloxicam, lidocaine and 0.5 mg/kg of meloxicam treatment prior to CPD. The researchers were blind to the treatment of calves to control the subjective error. The occurrences of actions associated with pain, which included head shaking, head rubbing, ear flicking, tail flicking, kicking, and head passing through the fence, were recorded. Physiological performance, including the respiration rate, heart rate, rectal temperature, mechanical nociceptive threshold (MNT), food intake, and daily activity level, was monitored. Hematological conditions were ascertained through the use of routine blood tests and enzyme-linked immunosorbent assay. The generalized linear mixed model was employed to analyze the data. The research findings revealed that applying the CPD procedure significantly elevated the frequencies of tail flicking, head shaking, and kicking, resulted in increases in respiratory rate, heart rate, daily active steps, and food intake and a decrease in MNT, and led to alterations in hematological markers, including platelet counts, mean platelet volume, prostaglandin E2, constitutive nitric oxide synthase, and hydroxyl radical. Considerable benefits, such as lower heart rates, higher food intake, and MNTs, as well as lower levels of white blood cell counts, lymphocyte counts, hemoglobin, mean platelet volume, prostaglandin E2, tumor necrosis factor-α, constitutive nitric oxide synthase, malondialdehyde, and hydroxyl radical, were observed in the calves that received meloxicam treatment in response to CPD. The findings of the study indicate that the co-administration of lidocaine and meloxicam provides obvious benefits in mitigating pain, inflammation, and oxidative stress in calves aged over 9 d and undergoing CPD. This endorses the use of meloxicam during the disbudding and dehorning procedures of calves.

Disbudding and dehorning practices for preweaned dairy calves by farmers in Wisconsin, USA

Many dairy farmers in North America disbud or dehorn their cattle to improve human and animal safety. The Farmers Assuring Responsible Management (FARM v. 4.0) program requires that disbudding be performed before 8 wk of age with pain-control medication. The objective of this observational cross-sectional study was to quantify disbudding and dehorning practices of Wisconsin dairy producers to target future extension programming. Responses from 217 Wisconsin dairy producers and calf raisers were collected via digital surveys distributed at extension events and through industry contacts. Of the 217 respondents, 188 performed on-farm disbudding themselves. Most respondents (61%) used caustic paste as their primary method, which was most commonly applied on the day the calf was born (53%). Hot iron was used by 32% of respondents, and surgical methods (gouge, scoop, or wire saw) were used by 6% of respondents. Hot-iron disbudding was most commonly performed at 4 to 8 wk of age (41%) and 1 to 4 wk of age (33%), whereas surgical methods were most commonly performed at 8 wk or older (73%). Pain-control medication was used by 43% of respondents. Specifically, 35% used an anti-inflammatory, and 21% used a local nerve block. Veterinary involvement in creating the disbudding protocol was associated with increased odds of using pain control. Respondents with a target weaning age of ≥10 wk had greater odds of complying with FARM disbudding requirements and were also more likely to use polled genetics. Respondents aged 18 to 34 and respondents with >60 calves were more likely to have made changes to their disbudding or dehorning protocol in the last decade. Although use of pain control was higher than in previous US studies, full adoption of pain management requires further extension efforts. Veterinarians appeared influential on adoption of pain control, and their involvement may encourage adoption of pain management. Further research should investigate how the implementation of new FARM v. 4.0 standards will change the disbudding and dehorning practices of American dairy producers.

The ACTH challenge and its repeatability in fattening bulls-influences of physiological state, challenge time standardization, and horn status

Adrenocorticotropic hormone (ACTH) challenges are frequently performed in repetition when evaluating stress or welfare in animals. To our knowledge, the repeatability of ACTH challenges in cattle, although fundamental to further studies of this type, has not yet been the subject of research. Therefore, the objective of this study was to evaluate the repeatability of ACTH challenges in fattening bulls of different horn status. Eight-one bulls were subjected to 3 consecutive ACTH challenges. The first challenge (C1) was performed in calves aged 1.5 mo. Subsequently, animals were characterized as high or low cortisol responders and either disbudded or left with horns. They were then assigned to 1 of 3 rearing groups: a horned group (H+), a disbudded group (H-), and a mixed group (M; 50% horned and 50% disbudded), with each group containing an equal number of high and low responders. The second ACTH challenge (C2) was performed at the age of 11 mo. Time of day (TOD) of challenge was either fixed (ST = same TOD) or alternated (AT = alternate TOD) between C1 and C2. The third ACTH challenge (C3) was performed 7 d after and at the same TOD as C2. Saliva samples were taken 60 and 30 min before and 30, 60, 90, 120, and 150 min after each intravenous ACTH injection. The area under the curve (AUC) was calculated with respect to both ground (AUC_G) and to increase (AUC_I). The AUC_I increased markedly between C1 and C2 (P < 0.05) in ST bulls, and no effects were observed for AUC_G between C1 and C2 in ST or AT bulls, nor for any AUC between C2 and C3 (P > 0.1). The overall repeatability of AUC_G and AUC_I between C1 and C2, reflecting the repeatability between 2 different physiological states, was poor and moderate, respectively, for ST bulls (AUC_G: r = 0.24, P > 0.1, intraclass correlation coefficient (ICC) = 0.21; AUC_I: r = 0.48, P < 0.01, ICC = 0.41) and lacked in AT bulls (AUC_G: r = 0.07, P > 0.1; ICC = 0.03; AUC_I: r = 0.08, P > 0.1, ICC = 0.06). The repeatability of AUC_G and AUC_I between C2 and C3, reflecting the repeatability within the same physiological state, was moderate (AUC_G: r = 0.59, P < 0.001; ICC = 0.53; AUC_I: r = 0.58, P < 0.001, ICC = 0.52). Assignment to high and low responder groups based on peak cortisol concentration in C1 did not persist over time. H+ bulls showed higher AUC_I in C2 and C3 (P < 0.1 and P < 0.05, respectively) than H- bulls. The M group differed from the H- group only in C3 (P < 0.05). Thus, the effect of horn status on ACTH challenges needs further investigation. In conclusion, our results report poor repeatability of the cortisol response to ACTH challenges for challenges performed in different physiological states and moderate repeatability for challenges performed within the same physiological state. Moreover, they point out the importance of standardization of TOD when performing repeated ACTH challenge.

Social approach and place aversion in relation to conspecific pain in dairy calves

Despite scientific interest in animal empathy, and growing public concern for farm animal welfare, the empathic abilities of farm animals remain under researched. In this study, we investigated empathic responses of young Holstein dairy calves to conspecifics recovering from hot-iron disbudding, a painful procedure common on dairy farms. A combination of social approach and place conditioning was used. First, 'observer' calves witnessed two 'demonstrator' calves recover from either a painful procedure (hot-iron disbudding and sedation) or a sham procedure (sedation alone) in distinct pens. Observer calves spent more time in proximity and paid more attention to calves recovering from the painful procedure compared to sham calves (proximity: 59.6 ± 4.3%; attention: 54.3 ± 1.5%). Observers were then tested for conditioned place aversion (in the absence of demonstrators) at 48h, 72h and 96h after the second demonstration; observers tended to avoid the pen associated with conspecific pain during the second of the three tests, spending 34.8 ± 9.6% of their time in this pen. No strong evidence of pain empathy was found, but our tentative results encourage further research on empathy in animals.

Assessment of potential neuropathic changes in cattle after cautery disbudding

Disbudding of calves is a standard husbandry procedure to reduce the risk of injuries to other cattle and to workers. Whereas acute pain resulting from disbudding has been studied extensively, little is known about chronic pain as a potential long-term consequence. The goal of the present study was to investigate possible morphological changes in the cornual nerve as a function of disbudding. Samples were collected from 17 randomly selected bulls and from 21 calves from a prospective clinical study. Among the calves, 13 were disbudded and 8 were sham-disbudded. Out of the disbudded calves, 4 showed signs of chronic pain. In all the animals, the infraorbital nerve was used as a methodological check. Morphological analysis included measuring minimal diameters of the axons present in both the cornual and infraorbital nerves. Sympathetic fibers were identified as based on the presence of Tyroxine hydroxylase (TH). TH-negative fibers were considered afferents. Trigeminal ganglia from the calves were immunostained for glial fibrillary acidic protein (GFAP) and Activating transcription factor 3 (ATF3). R. cornualis and N. infraorbitalis differed in terms of axon diameters and proportion of TH-positive fibers. Weak evidence (p > .091) of a difference in axon diameters between control and disbudded calves was found in R. cornualis, but the proportion of TH-positive fibers was alike in both groups. Average glial envelope and the percentages of ATF3-positive neurons revealed no difference between calves with and without signs of pain. Thus, available evidence is insufficient to support neuropathic changes as a result of disbudding in calves.

The effectiveness of clove oil and two different cautery disbudding methods on preventing horn growth in dairy goat kids

The effectiveness of clove oil and cautery disbudding on horn growth was evaluated in goat kids. The study used 243 Saanen doe kids (4±1 days old; mean±SD) on two goat farms that were disbudded with either (i) clove oil injection (CLOVE), (ii) a cautery iron and bud removed (BUDOFF), or (iii) a cautery iron with bud left intact (BUDON). Each kid received a different treatment per bud, which were balanced between buds (left/right) and randomly allocated. A trained observer monitored bud growth following treatment for 3 months recording either: N: no growth, H: normal horn, S: abnormal horn (scur), or SC: soft, fibrous lump (scorn). After the final observation, buds were assessed for the probability of detecting (i) success (no growth), (ii) scurs, (iii) horns or (iv) scorns [with 95% CI]. The probability of success for BUDOFF (0.77 [0.63, 0.87]) was higher than for BUDON (0.20 [0.11, 0.34]) and CLOVE (0.09 [0.04, 0.18]; P ≤ 0.05). Furthermore, the probability of success for BUDON was higher than for CLOVE (P ≤ 0.05). The probability of scurs was higher for CLOVE (0.72 [0.63, 0.80]) than BUDOFF (0.25 [0.17, 0.34]) and BUDON (0.30 [0.21, 0.39]; P ≤ 0.05). There was no difference in the probability of scurs for BUDOFF and BUDON (P > 0.05). The probability of horns was higher for CLOVE (0.21 [0.15, 0.29]) than BUDON (0.02 [0.01, 0.06]; P ≤ 0.05); horns were not observed for BUDOFF. The probability of scorns for BUDON, the only treatment that led to scorns, was 0.41 (0.25, 0.60). These results suggest that BUDOFF was more effective at preventing growth than CLOVE and BUDON and appears the most effective method, of the methods tested, for disbudding kids. Future research should explore other alternatives to cautery disbudding that may be both efficacious and cause less pain.

Can disbudding of calves (one versus four weeks of age) induce chronic pain?

BACKGROUND

Calf disbudding is a welfare-relevant invasive husbandry procedure. While it is widely recognized that disbudding elicits acute pain, its chronic consequences are currently unknown.

OBJECTIVES

Primary aim of this study was to investigate whether disbudding leads to chronic pain in calves; secondary aim was to evaluate the influence of age at disbudding (1 week versus 4 weeks).

METHODS

Thirty-four Holstein bull calves, enrolled in a prospective, controlled, randomized trial, underwent either early disbudding (ED) or late disbudding (LD) or sham treatment (control) at 1 and 4 weeks of age. Pain scoring and quantitative sensory tests (von Frey filaments and algometry) were performed at regular intervals up to 105 days of life; neurophysiological determination of nociceptive reflex thresholds and conditioned pain modulation (CPM) up to 90 days. Data was analyzed with the Brunner and Langer model followed by post-hoc test, with level of significance set at 0.05.

RESULTS

Thirty-one calves completed the data collection. Signs of chronic sensitization were observed in 38% of disbudded calves (4 in ED and 4 in LD). Pain scores (until 105 days) and allodynia scores (until 60 days) were significantly higher while pressure thresholds (until 105 days) were significantly lower in both groups ED and LD compared to control. Late disbudded calves showed impairment of trigeminal CPM. Lower laser-evoked trigeminal reflex thresholds were found in clinically painful calves compared to control.

CONCLUSIONS

The sequelae of disbudding can extend beyond the acute post-procedural phase. Chronic trigeminal sensitization, independently from the age at disbudding can affect individual calves.

Evaluating treatments with topical anaesthetic and buccal meloxicam for pain and inflammation caused by amputation dehorning of calves

To assess the effects of a topical anaesthetic (TA) and buccal meloxicam (BM) on behaviour, maximum wound temperature and wound morphology following amputation dehorning of beef calves, 50 unweaned Hereford calves were randomly allocated to: (1) sham dehorning / control (CON, n = 14); (2) amputation dehorning (D, n = 12); (3) amputation dehorning with pre-operative buccal meloxicam (DBM, n = 12); and (4) amputation dehorning with post-operative topical anaesthetic (DTA, n = 12). Videos of the calves were captured for 3 h following treatment. Each calf was later observed for 5 min every hour and the frequency and duration of specific behaviours displayed during these focal periods was recorded. Infrared and digital photographs of dehorning wounds were collected from all dehorned calves on days 1, 3 and 7 following treatment. Infrared photographs were used to identify the maximum temperature within the wound area. Digital photographs were used to score wounds based on visual signs of inflammation and healing, using a numerical rating scale of 1 to 3, with morphological aspects of inflammation increasing and morphological aspects of healing decreasing with progressive scores. CON calves displayed fewer head shakes than all dehorned calves at 2 and 3 h following treatment (P = 0.025). CON and DTA calves displayed less head turns than DBM calves at 2 h following treatment (P = 0.036). CON calves displayed fewer combined point behaviours than all dehorned calves at 2 h following treatment (P = 0.037). All dehorning wounds had a greater maximum temperature on days 3 and 7 compared to day 1 (P = 0.003). All wound morphology scores decreased from day 1 to day 3 and wound morphology scores of DBM and DTA calves increased from day 3 to day 7 (P = 0.03). Although flystrike may have confounded these observations, no clear effects of TA or BM on behaviour, maximum wound temperature or wound morphology following dehorning of calves were observed. Further research is required to evaluate the analgesic efficacy of these products for amputation dehorning of calves.

Effects of transdermal flunixin meglumine on pain biomarkers at dehorning in calves

The objective of this study was to evaluate the analgesic properties of transdermal flunixin meglumine when given at the time of dehorning on pain biomarkers. Twenty-four weaned male Holstein calves, 6 to 8 wk of age were enrolled into the study. The calves were randomly assigned to 1 of 3 treatment groups: 1) transdermal flunixin and dehorn (DH-FLU); 2) transdermal flunixin and sham dehorn (SHAM-FLU); and 3) placebo and dehorn (DH-PLBO). Transdermal flunixin at a label dose of 3.33 mg/kg (or placebo at an equivalent volume) was administered as a pour-on along the top-line of the calves in each treatment group concurrently with electrocautery dehorning or sham dehorning. Biomarker parameters collected and analyzed included: infrared thermography (IRT), mechanical nociception threshold (MNT), plasma cortisol, and substance P (SP). There were no differences in maximal temperatures detected for the IRT measurements of the medial canthus of the eye for the DH groups. Mean control point MNT measurements at 48 h were 3.14 kgF, 3.46 kgF, and 1.43 kgF for the DH-FLU, Sham-FLU, and DH-PLBO groups, respectively (P = 0.0001). No other differences of MNT were detected between the dehorned groups for the other test sites and time points. Plasma cortisol reached peak concentration at 20 min postdehorning for the DH-FLU and DH-PLBO groups and 10 min for SHAM-FLU group. Peak plasma cortisol concentrations were 32.0 ng/mL, 12.7 ng/mL, and 28.8 ng/mL for the DH-FLU, SHAM-FLU, and DH-PLBO groups, respectively. Cortisol concentrations were lower for the DH-FLU group at 90 min postdehorning compared to the SHAM-FLU and DH-PLBO groups ( = 0.04). Area under the effect curve (AUEC) were similar for all groups ( = 0.93). No statistical differences in SP concentrations between groups were detected for any of the time points. In conclusion, transdermal flunixin meglumine given at the time of dehorning did not provide substantial analgesia based on the pain biomarkers investigated. Further investigation into its role as part of a multimodal analgesic plan is warranted.

Comparison of an online learning module to hands-on training in teaching a cautery disbudding technique for dairy calves including cornual nerve block application

Disbudding and dehorning are common procedures on dairy farms. In a recent survey of Ontario dairy producers, 38% reported not using local anesthetic for these procedures. Use of pain control is important for both calf welfare and industry sustainability. Use of local anesthetic requires technical training, typically provided by a veterinarian, although online training videos also exist. Neither method has been studied for efficacy. Our objective was to compare an online module to hands-on training in teaching naïve participants (veterinary students) to effectively carry out a cornual nerve block and disbud a dairy calf. Participants were assigned to either an online or hands-on training group. Although no statistical differences were seen in success of the nerve block, online learners were less confident and had poorer technical skills. While online learning was surprisingly effective for a psycho-motor skill, best practices should include hands-on training.

Impact of carprofen administration on stress and nociception responses of calves to cautery dehorning

The objective of this study was to investigate the effects of carprofen administered immediately before cautery dehorning on nociception and stress. Forty Holstein calves aged approximately 6 to 8 wk old were either placebo treated and sham dehorned ( = 10) or cautery dehorned following administration of carprofen (1.4 mg/kg) subcutaneously ( = 10) or orally ( = 10) or a subcutaneous and oral placebo ( = 10) in a randomized, controlled trial. All animals were given a cornual nerve block using lidocaine before dehorning. Response variables including mechanical nociception threshold, ocular temperature, heart rate, and respiratory rate were measured before and following cautery dehorning for 96 h. Blood samples were also collected over 96 h following dehorning and analyzed for plasma cortisol and substance P concentrations by RIA. Plasma carprofen concentration and ex vivo PGE concentrations were also determined for this time period. Average daily gain was calculated for 7 d after dehorning. Data were analyzed using a linear mixed effects model with repeated measures, controlling for baseline values by their inclusion as a covariate in addition to planned contrasts. Dehorning was associated with decreased nociception thresholds throughout the study and a stress response immediately after dehorning, following the loss of local anesthesia, and 48 h after dehorning compared with sham-dehorned calves. Carprofen was well absorbed after administration and reached concentrations that inhibited ex vivo PGE concentrations for 72 h (subcutaneous) and 96 h (oral) compared with placebo-treated calves ( < 0.05). Carprofen-treated calves tended to be less sensitive ( = 0.097) to nociceptive threshold tests. Overall, at the dosing regimen studied, the effect of carprofen on sensitivity and stress following cautery dehorning was minimal. Consideration of route of administration and dose determination studies may be warranted.

Effect of Topically Applied Anaesthetic Formulation on the Sensitivity of Scoop Dehorning Wounds in Calves

The post-operative effects of three formulations of topical anaesthetic and a cornual nerve block on the sensitivity of scoop dehorning wounds in calves were compared in two trials. In Trial 1, 21 female Holstein dairy calves aged 8 to 24 weeks were randomly allocated to two groups: (1) scoop dehorning with a post-operative application of a novel topical anaesthetic powder (DTAP, n = 10); and (2) scoop dehorning with a post-operative application of a novel topical anaesthetic ethanol liquid (DTAE, n = 11). In Trial 2, 18 castrated male and 18 female Hereford beef calves aged 16 to 20 weeks were randomly allocated to four groups: (1) scoop dehorning with a pre-operative cornual nerve block of lignocaine (DCB, n = 9); (2) scoop dehorning with a post-operative application of the novel topical anaesthetic ethanol liquid from Trial 1 (DTAE, n = 9); (3) scoop dehorning with a post-operative application of a topical anaesthetic gel (DTAG, n = 9); and (4) sham dehorning (CON, n = 9). Sensitivity was assessed by scoring the behavioural response of calves to stimulation of the wound or skin at time points before and after treatment. In Trial 1, DTAP calves had a greater probability of displaying more severe responses than DTAE calves at 90 and 180 min (P < 0.001). In Trial 2, at 1 h, DTAG calves had a greater probability of displaying more severe responses than CON calves. At 2 h onwards, all dehorned calves had a greater probability of displaying more severe responses than CON calves (P < 0.001). There were no differences between the responses of DCB, DTAG and DTAE calves at any time point. Topical anaesthetic formulations result in almost immediate but temporary anaesthesia of the wound following scoop dehorning in calves and may provide a practical option for pain relief on-farm.

Separation from the dam causes negative judgement bias in dairy calves

Negative emotional states in humans are associated with a negative (pessimistic) response bias towards ambiguous cues in judgement tasks. Every mammalian young is eventually weaned; this period of increasing nutritional and social independence from the dam is associated with a pronounced behavioural response, especially when weaning is abrupt as commonly occurs in farm animals. The aim of the current study was to test the effect of separation from the cow on the responses of dairy calves in a judgement task. Thirteen Holstein calves were reared with their dams and trained to discriminate between red and white colours displayed on a computer monitor. These colours predicted reward or punishment outcomes using a go/no-go task. A reward was provided when calves approached the white screen and calves were punished with a timeout when they approached the red screen. Calves were then tested with non-reinforced ambiguous probes (screen colours intermediate to the two training colours). "GO" responses to these probes averaged (± SE) 72±3.6% before separation but declined to 62±3.6% after separation from the dam. This bias was similar to that shown by calves experiencing pain in the hours after hot-iron dehorning. These results provide the first evidence of a pessimistic judgement bias in animals following maternal separation and are indicative of low mood.

Reduction in pain response by combined use of local lidocaine anesthesia and systemic ketoprofen in dairy calves dehorned by heat cauterization

This study assessed the efficacy of ketoprofen for mitigating pain following dehorning with an electric cautery iron. Forty Holstein heifer calves, 4 to 8 wk of age, were randomized to receive a lidocaine cornual nerve block and either an injection of ketoprofen (3 mg/kg IM) or physiological saline, 10 min prior to dehorning. Cortisol was measured from serum obtained 10 min prior to dehorning and at 3 and 6 h post-dehorning. Calf behavior was video-recorded between 0 to 2, 3 to 5, and 6 to 8 h post-dehorning, and frequency of ear flicks, head shakes, head rubs, lying, standing, feeding, and grooming were recorded. Finally, 24-h intake of calf starter was recorded. There was no effect of treatment on cortisol (P > 0.1); however, ketoprofen-treated calves displayed less ear-flicks and total head behavior (P < 0.05), and tended to consume more starter (P = 0.09) than control calves. Ketoprofen is effective for mitigating behavioral effects of postsurgical pain following dehorning in 4- to 8-week-old calves.

An investigation into the practices of dairy producers and veterinarians in dehorning dairy calves in Ontario

The objective of this survey was to describe the current state of dehorning practices by dairy producers and veterinarians in Ontario and to identify opportunities to improve on existing practices. Two hundred and seven producers and 65 veterinarians completed a survey on dehorning practices during the summer of 2004. Seventy-eight percent of dairy producers dehorn their own calves; 22% use local anesthetics. Veterinarians dehorn calves for 31% of dairy clients; 92% use local anesthetics. Pain management was the most common reason for use of local anesthetics for both groups, while time (veterinarians) and time and cost (producers) were the most common reasons for lack of use. Producers who used local anesthetics were 6.5 times more likely to have veterinary involvement in their dehorning decisions. Thirteen percent of producers were unaware of the options for pain management. These results suggest that veterinarians should take the initiative to educate their clients about the options for pain management.

Factors affecting Canadian veterinarians' use of analgesics when dehorning beef and dairy calves

Data collected through a national, randomized mail survey (response rate 50%) were used to identify reasons why veterinarians were likely (i) to use analgesic drugs when dehorning calves, and (ii) to perceive dehorning without analgesia as very painful. Logistic regression analysis indicated that veterinarians were more likely to be analgesic users the more they perceived that dehorning without analgesia was painful (OR = 1.7, P < 0.001). Other positive influences were if the veterinarian worked in British Columbia or Alberta (OR = 5.9, P = 0.005), and if they were primarily in dairy practice (OR = 3.7, P = 0.012) rather than beef practice. This effect of dairy practice was negated if the veterinarian also perceived that owners were unwilling to pay for analgesia (interaction term: OR = 0.25, P = 0.038). Veterinarians were also less likely to perceive dehorning without analgesia as very painful if they perceived that owners were unwilling to pay (OR = 0.58, P = 0.029). However, this effect on pain perception was offset by concern for personal safety (OR = 2.7, P = 0.015). The results are consistent with the relatively high level of outreach about animal welfare among farmers and veterinarians in the western provinces. The results confirm that many veterinarians' approach to pain management for dehorning is influenced considerably by concern about cost. However, pain management for dehorning is not expensive and there is unequivocal evidence that dehorning calves without pain management causes significant distress. Continuing education of veterinarians should help to increase analgesic usage.

Stress responses in adult cattle due to surgical dehorning using three different types of anaesthesia

Dehorning adult cattle is a surgical procedure causing distress of varying intensities that can be reflected in behavioural changes and alterations in plasma cortisol levels. Stress responses during the dehorning process were evaluated in 18 Red Pied cows. The cows were divided into 3 groups of six and kept in tie-stall housing. Those in the first group were dehorned under general anaesthesia (GA) induced by intravenous administration of xylazine and ketamine. The second group was dehorned under sedation and local anaesthesia (SLA) induced by intramuscular administration of xylazine and local anaesthesia with lidocaine. The third group was dehorned under local anaesthesia (LA) with lidocaine. Dehorning was performed with a foetotomy wire. Blood samples were taken 0.5 h before dehorning to determine cortisol levels, and, by means of a central venous catheter inserted into the jugular vein, during surgery at 0, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 5, 6, 7 and 8 h post-surgery. Concurrently, occurrence of stress behaviours was assessed. Cortisol levels were measured by enzyme immunoassay (EIA). The lowest mean peak levels of plasma cortisol (82.53 +/- 6.04 nmol l(-1)), the most rapid return of plasma cortisol levels to baseline values (1.92 +/- 1.11 h), and the lowest occurrence of stress behaviours (2.38 +/- 5.83%) were noted in the SLA group. The highest mean peak levels plasma cortisol (113.86 +/- 25.65 nmol l(-1)), the slowest return of plasma cortisol levels to baseline values (3.83 +/- 2.18 h) and the most frequent occurrence of stress behaviours (65.48 +/- 28.72%) were observed in the LA group. There were significant differences between the SLA and LA groups in peak plasma cortisol levels (p = 0.011) and in occurrence of stress behaviours (p = 0.003). Sedation induced by intramuscular administration of xylazine in conjunction with local anaesthesia with lidocaine is considered the most suitable method of anaesthesia when dehorning adult cattle. Local anaesthesia with lidocaine alone was least suitable.

Validation of the acute electroencephalographic responses of calves to noxious stimulus with scoop dehorning

AIM

To validate use of the electroencephalogram (EEG) and a minimal anaesthesia model for assessment of noxious sensory input caused by scoop dehorning of calves.

METHODS

Twenty Friesian heifers weighing 125-178 kg were maintained under light general anaesthesia using halothane and an established protocol (minimal anaesthesia model). They were then dehorned using a scoop dehorner either with (DH+LA) or without (DH) a lignocaine ring block, and changes in the EEG and electrocardiogram (ECG) recorded. Median frequency (F50), 95% spectral edge frequency (F95) and total power (Ptot) were derived from the EEG data.

RESULTS

There were significant increases in the F50 (p<0.01) and F95 (p<0.01), and a decrease in Ptot (p<0.01) following dehorning in the DH group, but there were no changes in the DH+LA group. Transient bradycardia in the first 75 sec following dehorning was recorded in the DH group compared with both pre-treatment values in the same group and with the DH+LA group (p<0.001). Tachycardia was evident by 15 min after dehorning in the DH but not the DH+LA group.

CONCLUSIONS

The results validate use of the EEG and a minimal anaesthesia model for assessment of noxious sensory inputs in cattle.

Cerebral infarction and meningoencephalitis following hot-iron disbudding of goat kids

CASE HISTORY

Twelve of 150 goat kids, 4-10 days old, died 3 days after disbudding with a hot iron. Another 18 kids had been ill the previous day but survived following antibiotic therapy. Five of the dead kids were necropsied.

PATHOLOGICAL FINDINGS

There was necrosis and haemorrhage of the skin, subcutaneous tissues and frontal bone at disbudding sites in all five kids examined post mortem. Beneath disbudding sites in 4/5 kids there were bilateral, dark red, often cavitated areas of necrosis extending deep into the frontal cortex of the brain. Histologically, these areas consisted of coagulation necrosis, haemorrhage, vascular thrombosis and suppurative inflammation. Numerous bacteria, predominantly large Gram positive rods, were present in the necrotic brain tissue. In the remaining kid, bilateral areas of yellow discolouration and flattening of gyri in frontal lobes corresponded histologically to extensive polioencephalomalacia. A mixed growth of aerobes and anaerobes was cultured from the brain of one kid with suppurative lesions.

CLINICAL RELEVANCE

Thermal disbudding of neonatal kids is widely practised in dairy goat herds and is considered the method of choice for disbudding in New Zealand. However, the skull of goat kids is much thinner than that of calves and the safety margin for thermal injury to the brain is markedly reduced. This report highlights the risks associated with the technique and its potential as a welfare issue.

Calf response to caustic paste and hot-iron dehorning using sedation with and without local anesthetic

Dairy producers require effective methods of reducing the pain associated with dehorning. Previous work has shown that analgesics can reduce pain associated with hot-iron dehorning, but these interventions may not be practical for some producers. Some producers favor the use of caustic paste (to cause a chemical burn as opposed to thermal burn), but little is known about how to treat pain caused by caustic burns. In 2 experiments, head shaking and head rubbing behaviors were used to evaluate pain following dehorning using caustic paste. In experiment 1, sedated calves were dehorned using a caustic paste, with or without a lidocaine local block. Calves treated with lidocaine showed no evidence of reduced pain response in the hours after the caustic paste was applied. In experiment 2, response to caustic paste dehorning with a sedative only was compared with hot-iron dehorning using a sedative and local anesthetic. In the first 4 h after dehorning, calves dehorned with a hot iron showed more head shaking than calves dehorned with caustic paste. These results indicate that dehorning with caustic paste combined with a sedative results in less pain to calves than dehorning with a hot iron combined with a sedative and a local anesthetic.

Behavioural responses of calves to amputation dehorning with and without local anaesthesia

OBJECTIVE

To assess the pain elicited by amputation dehorning and evaluate the effect of local anaesthesia by using changes in calf behaviour.

METHODS

The behaviour of 6-month-old Friesian calves (n = 60), subjected to control handling, dehorned or dehorned after local anaesthesia treatment, was monitored in this study. The proportion of calves displaying particular behaviours was recorded using instantaneous scan sampling during the first 10 h and between 26 and 29 h after treatment.

RESULTS

The three behaviours of tail flicking, head shaking and ear flicking displayed similar features with time according to treatment and appeared to occur in an inverse relation to rumination. Dehorned calves were highly restless for the first 6 h after treatment. A significantly greater proportion of them displayed tail flicking, head shaking and ear flicking than the control calves, which, by contrast, stood still and ruminated (P < 0.05). The behaviour of calves given local anaesthetic prior to dehorning was similar to that of the control calves for the first 2 h. Thereafter the proportion of calves displaying tail flicking, head shaking and ear flicking increased, rumination decreased, and the behaviour was similar to that of the dehorned calves.

CONCLUSIONS

These results suggest that dehorning is a painful experience that lasts about 6 h and that local anaesthetic alleviates that pain during its period of action. It is recommended that local anaesthetic be administered when conducting amputation dehorning.

Dehorning and disbudding distress and its alleviation in calves

Dehorning and disbudding are routine painful procedures carried out on cattle to facilitate management. The pain caused by these procedures and its alleviation may be evaluated by monitoring behaviour and physiological responses, and by measuring their effects on weight gain. The cortisol response to cautery disbudding is significantly smaller than that to amputation dehorning which infers that the latter is more painful. Amputation dehorning stimulates a defined cortisol response with a rapid rise to a peak value within 30 min followed by a decline to a plateau which then declines to pre-treatment values after about 8 h. A cornual nerve blockade using lignocaine virtually eliminates the escape behaviour seen during disbudding and dehorning and reduces the plasma cortisol response to dehorning for about 2 h. Thereafter there is an increase in the plasma cortisol concentration, a delayed response, which lasts for about 6 h. A cornual nerve blockade, using lignocaine combined with cauterizing the wound caused by amputation dehorning, virtually eliminates the cortisol response as does combining a lignocaine blockade with the non-steroidal anti-inflammatory drug (NSAID) ketoprofen. When xylazine is combined with a cornual nerve blockade using lignocaine before dehorning, the cortisol response is virtually eliminated for about 3 h. When this regime is used before cautery disbudding and includes a NSAID given before and after disbudding the behaviour of calves so treated suggests that pain may be alleviated for 24 h. Cautery disbudding is preferable to amputation dehorning, but for optimal pain relief xylazine sedation, local anaesthesia and a NSAID should be used with both procedures.

Routine surgical procedures in dairy cattle under field conditions: Abomasal surgery, dehorning, and tail docking

This article discusses the different methods used for the correction of left displaced abomasum. The advantages, disadvantages, and success rates of each technique are reviewed. The most common complications are described, and the economics of repeat surgery after a failed left displaced abomasum repair are examined. This article also addresses the need for anesthesia when dehorning and tail docking dairy cattle. The justifications for routine use of these two procedures are discussed, mainly from an animal welfare standpoint.

The utility of ketoprofen for alleviating pain following dehorning in young dairy calves

To determine if ketoprofen, in addition to local anaesthesia, reduces pain following dehorning, we experimentally dehorned dairy calves, less than 2 weeks of age, with (20 calves) or without (20 calves) intramuscular injections of ketoprofen. All calves received a local anesthetic (lidocaine) prior to dehorning and were dehorned with heat cauterization. Cortisol concentration was measured via jugular blood samples taken immediately before dehorning and at 3 and 6 hours following dehorning. Calf behavior was recorded between 0 and 2, 3 and 5, and 6 and 8 hours following dehorning. There was no significant (P > 0.10) effect on creep feed consumption, cortisol concentration, or any of the behavioral measures during the time periods studied. However, the difference in cortisol concentrations from the time of dehorning until 3 hours later was significantly lower (P < 0.05) in the ketoprofen-treated group. These results suggest that ketoprofen, in addition to local anesthesia, may alleviate short-term pain following dehorning with a butane dehorning device in dairy calves less than 2 weeks of age.

Cortisol responses to dehorning of calves given a 5-h local anaesthetic regimen plus phenylbutazone, ketoprofen, or adrenocorticotropic hormone prior to dehorning

The purpose of this work was to assess whether the non-steroidal anti-inflammatory drugs (NSAIDs) phenylbutazone and ketoprofen, and an adrenocorticotropic hormone (ACTH) induced cortisol surge, reduce the cortisol response which occurs when the local anaesthetic wears off in calves following dehorning. There were four control groups and one dehorned group; also four groups were given local anaesthetic lasting 5h and were dehorned without or with phenylbutazone, ketoprofen or an ACTH injection, one group was injected with ACTH twice (at 0 and 6h) and another received ACTH and 6h later was dehorned. Blood samples were taken before and after dehorning and plasma cortisol concentrations were determined by radio-immunoassay. Dehorning increased the mean plasma cortisol concentrations [max 137 (11)nmoll(-1)] above control values [38 (5)nmoll(-1)] for about 7h, whereas local anaesthesia maintained concentrations at control values until about 5h after dehorning, and then they became elevated until about 10h. The maximum rise in mean concentration which occurred when the local anaesthetic wore off [128 (32)nmoll(-1)] was not affected when phenylbutazone was given before dehorning [141 (28)nmoll(-1)], but was reduced significantly when ketoprofen [65 (17)nmoll(-1)] or ACTH [61 (19)nmoll(-1)] were injected before or at the time of dehorning, respectively. Marked cortisol responses to ACTH injected at 0 and 6h were similar, but the early part of the cortisol response to dehorning 6h after an ACTH injection was reduced. It is suggested that the delayed cortisol response, which began 5h after dehorning, arose both from ketoprofen-sensitive and cortisol-sensitive sensory input as well as from other factors. Phenylbutazone did not affect the sensory input from the amputation wounds in the present calves.

A comparison of catecholamine and cortisol responses of young lambs and calves to painful husbandry procedures

AIM

To compare the changes in plasma concentrations of noradrenaline, adrenaline and cortisol in lambs after ring castration plus tailing and in calves after dehorning with or without prior local anaesthesia.

METHODS

Male lambs were castrated and tailed with rings and calves were dehorned by amputation using a scoop with or without prior local anaesthesia. Blood samples were taken before and after treatment and plasma concentrations of noradrenaline, adrenaline and cortisol were determined.

RESULTS

Castration plus tailing of lambs resulted in a rapid increase in noradrenaline concentrations, a lack of an adrenaline response and a marked increase in cortisol concentration. There were similar changes in catecholamine concentrations in calves that were dehorned both with and without local anaesthetic, with adrenaline being elevated within 5 min of treatment and noradrenaline exhibiting a more protracted response. Dehorning caused a marked cortisol increase which was reduced to control concentrations by local anaesthesia for as long as the associated nerve blockade lasted.

CONCLUSIONS

The very short-lived adrenaline responses in calves were attributed to dehorning-induced nociceptor input leading to sympathetic stimulation of the adrenal medulla. The longer lasting noradrenaline responses in lambs and calves were thought be due to 'wash-out' of noradrenaline from damaged tissue associated with rings and amputation wounds, respectively.

Effect of local anaesthetic combined with wound cauterisation on the cortisol response to dehorning in calves

OBJECTIVE

To reassess whether local anaesthesia before dehorning and wound cauterisation after dehorning eliminates the cortisol response to dehorning.

METHODS

A control group was compared with three dehorned groups (dehorned alone, dehorned after local anaesthesia, dehorned after local anaesthesia then cautery of the amputation wounds). The local anaesthetic regimen used produced nerve blockade for about 5 h. Blood samples were taken before and after dehorning and plasma cortisol concentrations were determined.

RESULTS

Dehorning caused a marked cortisol response lasting for about 7 h. Local anaesthetic reduced the plasma cortisol concentrations to control values for 5 h, after which they increased for a further 5 h. Subsequently in both groups, cortisol concentrations remained at control values until at least 24 h after treatment. Local anaesthetic combined with wound cautery virtually abolished the cortisol response until at least 24 h after dehorning.

CONCLUSION

Combining local anaesthesia with cautery of the amputation wounds substantially reduced the cortisol response until at least 24 h after dehorning.

Reducing pain after dehorning in dairy calves

We investigated behavioral responses after dehorning and a sham procedure in 20 Holstein calves aged 4 to 8 wk. Calves either received a nonsteroidal antiinflammatory drug (ketoprofen) before dehorning as well as 2 and 7 h after the procedure or were assigned to a control group. All calves received a sedative (xylazine) and local anaesthetic (lidocaine) before dehorning, and responses were scored over 24 h after the procedure. After hot-iron dehorning, calves treated with ketoprofen also demonstrated little head shaking or ear flicking, but control animals demonstrated higher frequencies of these behaviors; both responses peaked 6 h after dehorning. Differences between the treatment groups remained statistically significant until 12 h (head shaking) and 24 h (ear flicking) after dehorning. A low frequency of head rubbing was observed in both treatment groups, but control calves were more frequently observed engaged in this behavior. There was no statistically significant effect of treatment on any of the other behavioral measures. Calves treated with ketoprofen also tended to gain more weight (1.2+/-0.4 kg) during the 24 h after dehorning than did control calves (0.2+/-0.4 kg). There was no effect of treatment on any of the response variables when calves were sham dehorned. These results indicate that ketoprofen mitigates pain after hot-iron dehorning in young dairy calves.

Behavioural, endocrine and cardiac responses in young calves undergoing dehorning without and with use of sedation and analgesia

Behaviour, plasma cortisol and heart rate were measured in 4-6-week-old calves during and after dehorning with and without the use of sedation and analgesia. Six groups of eight Friesian male and female calves were studied; four groups were dehorned using an electrical cauterizing dehorner, heated to approximately 600 degrees C. In group 1, a cornual nerve block was performed and the animals were sham-dehorned using a cold dehorner. Group 2 was treated similarly but dehorned with the heated dehorner. Group 3 received a mixture of xylazine and butorphanol intramuscularly, and were hot dehorned 20 min after the injection. Group 4 received the same sedatives-analgesics as group 3, and after 5 min also had a cornual nerve block, followed by hot dehorning 15 min later. Group 5 was hot dehorned without any form of sedation or analgesia. A sixth group of calves without any treatment or handling was used as controls for the behavioural observations. Head and leg movements during dehorning were significantly reduced when the cornual nerve was blocked. During the 4 h after dehorning, the behaviour of calves having a cornual block continued to differ from those in group 5. The cornual block prevented short-term increases in plasma cortisol concentrations and the long-term increases in heart rate seen in group 5. It was concluded that routine field use of local analgesia using a cornual nerve block improved the welfare of young calves subjected to dehorning with a hot iron.

Effects of local anaesthesia of 4 to 8 hours' duration on the acute cortisol response to scoop dehorning in calves

OBJECTIVE

To determine the effect of a long-acting local anaesthetic on the plasma cortisol response in calves dehorned using a scoop.

DESIGN

A physiological study with controls.

PROCEDURE

Seventy female calves, 3 to 4 months old, were divided into seven groups and dehorned by scoop with or without a long acting local anaesthetic (bupivacaine) which provides local anaesthesia for 3 to 4 h. In some treatment groups the local anaesthetic was given a second time, after 4 h, to give 8 h of anaesthesia. Blood samples were taken before and for 9 h after treatment and plasma cortisol concentrations were measured.

RESULTS

Scoop dehorning caused a marked rise in plasma cortisol concentration, which returned to pre-dehorning values after 7 h. The cortisol concentrations of calves given bupivacaine were similar to those of control animals for 4 h after dehorning, but then a significant and protracted rise occurred, with concentrations returning to pretreatment values at about 9 h after dehorning. In calves given a second treatment of bupivacaine 4 h after dehorning, the plasma cortisol concentration remained similar to control values for 8 h after dehorning but then increased sharply.

CONCLUSIONS

During its period of activity long-acting local anaesthetic prevented the rise usually seen after scoop dehorning in plasma cortisol concentrations; by inference it also alleviated the pain-induced distress caused by this procedure. However, when its effects had worn off the plasma cortisol values rose sharply indicating that animals still experienced pain-induced distress despite local anaesthetic being administered.

Effects of regional analgesia and/or a non-steroidal anti-inflammatory analgesic on the acute cortisol response to dehorning in calves

The effect of using a non-steroidal anti-inflammatory analgesic (ketoprofen) on the plasma cortisol response in calves dehorned with or without regional analgesia was determined. One hundred calves divided into 10 groups, four control and six dehorned, were used. Blood samples were taken before and after dehorning and plasma cortisol concentrations were measured. Dehorning caused a marked rise in plasma cortisol concentrations which returned to pretreatment levels after seven hours. The animals given ketoprofen before dehorning had a cortisol response similar to the dehorned animals for the first 1.3 hours after dehorning but then the plasma cortisol concentration returned to pretreatment levels. When animals were given a regional analgesic and ketoprofen the plasma cortisol concentrations were similar to control animals which had not been dehorned, with a small increase in plasma cortisol concentrations for the first hour after dehorning and then a rapid return to pretreatment values. This response was significantly lower than that seen in calves which received only regional analgesia. The results of this study suggest that a systemic analgesic should be combined with regional analgesia if the distress associated with dehorning is to be abolished.

Acute cortisol responses of calves to four methods of dehorning by amputation

OBJECTIVE

To measure the plasma cortisol response in calves dehorned by four different methods (scoop, guillotine shears, saw, embryotomy wire) for 9 h after dehorning.

DESIGN

A physiological study with controls.

PROCEDURE

Horn amputation was carried out on calves restrained manually in a race.

RESULTS

The four methods of dehorning provoked similarly increased cortisol responses which lasted for 6 h. During the first hour after dehorning the plasma cortisol concentrations were similar to those following ACTH injection. The overall cortisol response to control handling was about 30% of the responses to dehorning.

CONCLUSIONS

The similarity of the cortisol responses produced by the four methods of dehorning suggests that the distress experienced by calves following dehorning by amputation is similar regardless of method used.

Acute cortisol responses of calves to scoop dehorning using local anaesthesia and/or cautery of the wound

OBJECTIVE

To measure plasma cortisol responses in calves dehorned using a scoop after administration of local anaesthesia and/or cautery of the wounds.

DESIGN

A physiological study with controls.

PROCEDURE

There were six treatments: control handling with and without local anaesthesia, dehorning, dehorning after local anaesthesia, dehorning followed by wound cautery, and dehorning after local anaesthesia followed by wound cautery. Blood samples were taken before and after dehorning.

RESULTS

Dehorning caused an increase in plasma cortisol concentrations, which decreased a little to plateau values and then declined to pretreatment values 3 to 4 h after dehorning. The peak was smaller after local anaesthesia was administered but when its effects wore off, cortisol concentrations increased and thereafter were similar to those in the dehorned animals. The combination of local anaesthesia and cautery resulted in a plasma cortisol response similar to those in control calves with or without local anaesthesia.

CONCLUSIONS

If plasma cortisol concentrations reflect the distress being experienced by the calves, then local anaesthesia reduces the acute distress for about 3 h after dehorning but not during the subsequent 3 to 4 h. Combining local anaesthetic and cautery prevented the significant increase in plasma cortisol following dehorning and may eliminate the acute distress caused by scoop dehorning.

Cosmetic dehorning in goats

OBJECTIVE

This article describes a technique using primary closure when dehorning goats, and report the results of 22 cases.

STUDY DESIGN

Medical records of goats that had cosmetic dehorning were reviewed.

ANIMALS OR SAMPLE POPULATION

Twenty-two goats.

METHODS

The medical records of 22 goats, not previously dehorned by other methods, that were cosmetically dehorned between January 1988 and September 1995 were reviewed. Data retrieved from the medical record included age, breed, sex, surgical technique used for dehorning, and any complications that occurred after surgery. All clients were contacted by telephone to determine the course of postoperative healing for each goat. A surgical technique to remove the horns and close the defect primarily was described.

RESULTS

The mean age of the goats, all male Nubian or Nubian-Spanish cross, was 6.9 months (range, 2 to 24 months). Horn base diameter ranged from approximately 2 to 4 cm. Mean time from surgery until follow-up was 12.9 months (range, 3 to 57 months). All incisions healed by first intention in 10 to 14 days. Clinical signs of sinusitis were not noted, and owners were pleased with the healing time and cosmetic result obtained.

CONCLUSIONS

Primary closure of skin defects after dehorning of goats can be achieved with minimal postoperative care and excellent cosmetic appearance.

CLINICAL RELEVANCE

Primary closure after dehorning in mature goats reduces aftercare.

[Ethological, physiological and histological aspects of pain and stress in cattle when being dehorned]

The behaviour of 101 calves was evaluated during (n = 73) and after (n = 28) thermical dehorning without anaesthesia. Cortisol in saliva (n = 68) was measured in 68 calves. A simulation of dehorning was carried out as a control in most of the animals. The area around the horn bud was examined histologically in 20 calves of different ages (newborn until 3-4 months old). Additionally, the influence of dehorning cows with a wire-saw under anaesthesia on behaviour (n = 16), cortisol in saliva (n = 23), and the milk yield was examined. Independent of the calves' age, the horn bud and the surrounding hairy area were well innervated. For all calves dehorning without anaesthesia was a painful experience. During dehorning calves showed distinct pain and defense reactions. Most reactions were observed more often when the calves were dehorned as when dehorning was simulated. The cortisol in saliva was significantly increased after dehorning. In summary, we have to conclude that calves have a well developed nociceptive system from birth on. Therefore calves should only be dehorned using anaesthesia. Despite the anaesthesia, dehorning was stressful for the cows, as measured by a significant increase of cortisol in saliva. Moreover, cows showed pain reactions when the effects of the anaesthesia diminished. Dehorning had only a short effect on the milk yield of the cows.

Invasive malignant fibrous histiocytoma in a cow

An invasive malignant fibrous histiocytoma associated with the left cornual process, and causing lysis of the frontal bone, was diagnosed in a cow. The mass compressed the left cerebral hemisphere focally and extended into the frontal sinus and ethmoid and nasal turbinates. It was composed of pleomorphic to spindle-shaped cells with ultra-structural evidence of fibroblastic, myofibroblastic, and fibrohistiocytic differentiation. Trauma and chronic inflammation may be predisposing factors for development of neoplasia in cattle.

Surgical (cosmetic) dehorning in cattle

Numerous methods have been developed through the ages to dehorn cattle. Some are clever and sophisticated; others are crude. Most methods can be used effectively and humanely, and with desirable cosmetic results. This article discusses the cosmetic and ethical considerations for dehorning, as well as surgical preparation and techniques used.

Dehorning the adult goat

Although goats are ideally disbudded as infants, occasionally they are not. Goats grow horns much more rapidly than most owners realize and use these horns on other goats and, occasionally, people. Dehorning adult goats is not as easy as dehorning cattle. The techniques for tranquilizing, anesthetizing, and dehorning adult goats is described and aftercare is discussed.

[Dehorning of goats and kids]

The local anaesthesia used during the dehorning of goats is described. The authors recommend general anaesthesia for the disbudding (dehorning) of kids. In addition to the dehorning of goats and kids, this article also describes the use of the combination of xylazine, ketamine, and atropine, and the preparation of this 'goat anaesthetic'.