Wound healing after mulesing and other options for controlling breech flystrike in Merino lambs: quantitative and semiquantitative analysis of wound healing and wound bed contraction

Background A two‐part study examined wound healing and contraction occurring after mulesing and two alternative methods of preventing breech flystrike in sheep. Objective To quantify wound healing using a scoring system and to assess the contractility of the wound bed of the breech after mulesing, cetrimide‐intradermal treatment and application of clips. Method The study group of 30 mulesed, 30 cetrimide‐intradermal treated, 30 control and 10 clip‐treated sheep were humanely killed at six time points from 3 to 47 days after each treatment. Wound healing post treatment was assessed using a scoring system, and contractility was assessed by the quantification of myofibroblast expression. Statistical analyses allowed comparisons of temporal wound healing and contraction between treatment groups. Results Mulesing wounds healed faster in the first 11 days, but by 19 days wound healing was similar between the mulesing and cetrimide‐intradermal groups. By 32 days, all three treatment groups had similar wound healing scores. There was greater myofibroblast expression in the mulesing group in the first 11 days after treatment, but by 19 days expression was similar in both the mulesing and cetrimide‐intradermal groups. The clip group had significantly less myofibroblast expression from 32 days after treatment. Conclusion Wound healing is initially most rapid after mulesing, but there are similar wound healing scores in the mulesing and cetrimide‐intradermal treatment groups by 19 days. Both mulesing and the cetrimide‐intradermal treatment induce a similar amount of wound bed contraction, with less contraction observed after application of clips.     

EEG changes in 4-week-old lambs in response to castration, tail docking and mulesing

OBJECTIVE: To interpret changes in EEG in relation to perceived pain of castration, mulesing and docking in lambs. DESIGN: Analysis of covariance (randomised block design) to determine the effects of treatment on eight bandwidths of the EEG frequency spectrum. PROCEDURE: Ninety-eight, 3- to 4-week-old lambs were subjected to one of seven treatments: castration, tail docking, mulesing, ear tagging, sham shearing, formalin injection (to induce lameness) and handling. EEG was recorded for 15 min before treatment, during treatment, and for 15 min after treatment. RESULTS: Consistently lower mean power values across all bandwidths of the EEG were found at the time of mulesing and docking than at handling and shearing (P < 0.01). Formalin injection resulted in lower power values than handling and shearing (P < 0.01). Castration had lower power values than handling and shearing. Similarly, for 15 min after treatment, mulesing and formalin injection had significantly lower power values than handling, shearing, ear tagging and castration (P < 0.05). CONCLUSION: The consistent effects associated with mulesing, docking and castration compared to handling, shearing and ear tagging suggest that mulesing at both the time of treatment and during 15 min after treatment results in a response that is similar to that of induced lameness. Docking and castration result in a response at the time of treatment that is similar to induced lameness and mulesing, but during 15 min after treatment is similar to the non-noxious control treatments. However, the depressing effects on the mean power values are the reverse of that anticipated from a previously developed pain model, highlighting the need for further research to develop this technology to evaluate pain associated with husbandry procedures.     

A comparison of stress in surgically and non-surgically mulesed sheep

Summary A comparison has been made in 9- to 10-month-old castrated male Merino sheep of the changes in plasma total cortisol concentration and behaviour after being treated by either the modified Mules operation or by topical application of a quaternary ammonium compound to achieve non-surgical mulesing. After surgical mulesing, plasma total cortisol concentration increased immediately and rapidly and reached a peak value in 15 minutes, whereas after non-surgical treatment an immediate rise did not occur, but a similar peak value was observed in blood samples collected 24 hours after treatment. The concentrations were lower in both groups at 48 hours. Likewise postural changes indicative of discomfort were immediately apparent in the surgically treated sheep, but not until 3 to 4 hours later in those treated non-surgically. Arena testing revealed that a lasting aversion to the person who restrained them during treatment developed in the surgically mulesed sheep, but not in those treated non-surgically. The non-surgical procedure did not create large open wounds, as did the surgical operation, but still achieved similar enlargement of the bare area on the breech, and healing was quicker in the non-surgically treated sheep.     

Haematological, biochemical and selected acute phase protein reference intervals for weaned female Merino lambs

Background   Merino lambs are currently the subject of much research into the welfare aspects of mulesing and mulesing alternatives.
Objective   Obtain haematology, biochemistry and acute phase protein reference intervals using modern methodologies for female Merino lambs.
Method   Blood was collected from 50, weaned, 9- to 16-week-old, female Merino lambs. Haematology and biochemistry panels were performed using routine automated methods. The acute phase proteins, fibrinogen, serum amyloid A and haptoglobin, were also measured using commercially available techniques. The reference intervals were determined to be the central 95% of results.
Results   Differences in the concentrations for some analytes were seen when compared with reported studies in sheep, but may be explained by the use of sheep of a different signalment, as well as different methodologies for analyte measurement. Overall, most analytes gave similar values to those previously reported in other studies. Notable exceptions were alkaline phosphatase, phosphate and globulins, for which the different results were often attributed to the younger age of the sheep in the present study, and platelets and creatine kinase, for which the elevated levels may have been a result of stress and muscle exertion associated with blood collection and husbandry practices.
Conclusion   Established haematological, biochemical and acute phase protein reference intervals are necessary for the investigation of the systemic impact of mulesing and mulesing alternatives and for the investigation of systemic diseases affecting weaned, 9- to 16-week-old, female Merino lambs in general.     

Effects of meloxicam or tolfenamic acid administration on the pain and stress responses of Merino lambs to mulesing

OBJECTIVE: To determine the effectiveness of two long-acting non-steroidal anti-inflammatory drugs (NSAIDs) at reducing the pain and stress responses to mulesing in lambs. PROCEDURES: Merino lambs (n = 60) were allocated at 5 weeks of age to six treatment groups: (1) sham mules; (2) mules; (3) tolfenamic acid-sham mules; (4) tolfenamic acid administered 45 min before mulesing; (5) tolfenamic acid at the time of mulesing; (6) meloxicam at the time of mulesing. Plasma cortisol was measured at -0.75, -0.25, 0, 0.5, 1, 3, 6, 12, 24, 48 and 72 h relative to mulesing. Beta-endorphin concentrations in plasma were determined at 0, 0.5, 1, 6, 12, 24, and 48 h. Haematology was performed on blood samples taken at -0.75, 0, 24, 48 and 72 h. Plasma haptoglobin was measured at 0, 12, 24, 48 and 72 h. Rate of wound healing was determined 72 h post mulesing, and animal behaviour, including posture, was measured for 6 h after mulesing. RESULTS: The mulesed lambs exhibited large increases in plasma concentrations of cortisol, beta-endorphin and haptoglobin. All mulesed animals lost weight significantly in the week after mulesing, regardless of analgesic administration, but the difference in weight between mulesed and unmulesed lambs was less at the final measurement, 2 weeks after mulesing. Mulesed lambs spent significantly less time lying ventrally than control lambs. All lambs that were mulesed, including those administered NSAIDs, spent more time standing with a hunched posture and less time walking normally than control lambs. CONCLUSIONS: The NSAID treatments applied 45 min before or at the time of mulesing at the dose levels used in this study were not effective in reducing the acute response of lambs to mulesing.     

Observations on the indirect transmission of virulent ovine footrot in sheep yards and its spread in sheep on unimproved pasture

SUMMARY: Virulent ovine footrot was transmitted accidentally to a group of 23 adult Merino sheep (flock B) after holding for 1 hour in sheep yards, which earlier the same day had contained another flock (flock A) with < 1% prevalence of sheep with footrot lesions. Sheep in flock B were rendered susceptible to virulent footrot by grazing 600 mm high unimproved pasture dominated by paspalum ( Paspalum dilatatum ) and kangaroo grass ( Themeda australis ) during warm, humid and wet weather. In addition to moisture, interdigital abrasions caused by the pasture might have predisposed the interdigital skin to infection with Dichelobacter nodosus .     

COMPARATIVE ABILITY OF HYBRID AND HOMOZYGOUS RESISTANT LARVAE OF LUCILIA CUPRINA TO CAUSE STRIKES UNDER EXPERIMENTAL CONDITIONS

The intervals between the jetting of sheep with dieldrin or BHC, and the inducement of flystrike by implants of hybrid and homozygous BHC/dieldrin resistant larvae of Lucilia cuprina, were compared. Flystrikes soon established with homozygous resistant larvae, but considerable protection was afforded against hybrid larvae, the interval being longer with BHC than with dieldrin. Dieldrin was shown to have a residual effect on rr larvae in a mixed population 9 weeks after jetting. It is suggested that wide adoption of mulesing and mid-season's crutching would favour reversion to susceptibility in the blowfly and thus extend the field life of insecticides to which resistance has emerged.     

The effect of a topical anaesthetic formulation, systemic flunixin and carprofen, singly or in combination, on cortisol and behavioural responses of Merino lambs to mulesing

OBJECTIVE: To determine the pain responses of lambs to mulesing, and the effectiveness of potential analgesic treatments. PROCEDURES: Merino lambs (n=64) were allocated at 5 weeks of age to eight treatment groups: 1) sham mules; 2) conventional mules; 3) topical anaesthetic, incorporating lignocaine, bupivicaine, adrenaline and cetrimide, applied immediately after mulesing; 4) flunixin + topical anaesthetic, with flunixin administered 2.5 mg/kg s.c. 90 min before mulesing; 5) carprofen + topical anaesthetic, with carprofen administered 4 mg/kg s.c. 90 min before mulesing; 6) carprofen, administered as above; 7) flunixin, administered as above; and 8) carprofen + flunixin, administered as above. Plasma cortisol was measured at 0, 0.5, 6, 12 and 24 h relative to mulesing. Animal behaviour, including posture, was recorded for 12 h after mulesing. RESULTS: The conventional mules lambs exhibited large increases in plasma cortisol, reduced lying and increased standing with a hunched back compared with sham mules animals. Topical anaesthetic reduced the cortisol peak to mulesing and hunched standing, and increased lying compared with the conventional mules treatment, but generally did not result in values equivalent to sham mules animals. Carprofen, flunixin, and carprofen + flunixin treatments did not reduce the cortisol response to mulesing but substantially ameliorated some changes in behavioural postures. Flunixin + topical anaesthetic reduced the cortisol peak following mulesing and substantially ameliorated most changes in behavioural postures. Carprofen + topical anaesthetic abolished the cortisol peak following mulesing and substantially ameliorated most changes in behavioural postures. All mulesed animals lost weight in the week after mulesing regardless of analgesic administration, but there were no significant differences in growth rate between any of the eight treatments over the 3 weeks after mulesing. CONCLUSIONS: Analgesics can moderate the pain response of lambs to mulesing. The welfare outcome for lambs of mulesing could be improved by use of a combination of local anaesthetic and long acting non-steroidal anti-inflammatory drug.     

Animal welfare provision for land-based livestock industries in Australia

The land-based livestock industries in Australia face particular challenges in assuring high animal welfare standards due to large land areas and stock numbers, climatic extremes and relatively low inputs in terms of manpower and infrastructure. These factors make a major contribution to welfare issues associated with nutrition, health, mustering and handling, and transportation. In addition, welfare is seriously compromised by the invasive procedures that are conducted on livestock, such as castration, dehorning, mulesing and tail-docking. At least partial solutions to welfare issues associated with nutrition, health, mustering and handling are available now and should be universally adopted. There are potential solutions available for castration and dehorning, which require some further research and development. Genetic technologies can also provide a solution for dehorning, mulesing and tail-docking. Inevitably, all livestock experience transportation, and research and development is required to determine optimal practices for Australian conditions in order to minimise the negative impacts on animal welfare.     

A survey of the prevalence of blowfly strike and the control measures used in the Rûens area of the Western Cape Province of South Africa

Blowfly strike and the methods used to combat blowfly strike were recorded on 33 properties in the R?ens area of South Africa during 2003/2004. Data were recorded on Merino and Dohne Merino hoggets (n = 4951) with at least 3 months' wool growth. The following data were captured: presence or absence of strike, site of the strike (body or breech), presence or absence of dermatophilosis as well as subjective scores for wool quality and wool colour. Control measures recorded include: chemical treatment (preventative and spot treatment), crutching, mulesing and the use of the Lucitrap system. Blowfly strike was not significantly influenced by gender or breed. Hoggets suffering from dermatophilosis were more likely to be struck, compared with contemporaries not suffering from the skin disorder (0.057 vs 0.027; P < 0.05). Merino hoggets generally had higher scores than their Dohne Merino contemporaries for wool quality (32.6 vs 27.4; P < 0.05) and wool colour (29.0 vs 27.2; P < 0.05). There was an indication that the Lucitrap system may have reduced flystrike, but the effect was not statistically significant (P = 0.19 for overall strikes and P = 0.12 for body strike). The Mules operation benefited overall flystrike (0.013 vs 0.110; P < 0.05); mainly through an effect on breech strike (0.010 vs 0.109; P < 0.05). The proportion of fly strikes increased with wool length, and declined with an increase in farm size in wool colour score. None of the ethically acceptable control measures assessed could substantially reduce blowfly strike on their own, and an integrated pest management programme was proposed.     

Dermal and serological response against Pseudomonas aeruginosa in sheep bred for resistance and susceptibility to fleece-rot

Genetically select lines of Merino sheep have been bred at Trangie (NSW Agriculture and Fisheries) for resistance (R) or susceptibility (S) to fleece-rot and flystrike. It is believed that fleece characters are primarily responsible for the R or S phenotype. When transferred to the wetter coastal environment of Sydney, R and S sheep with no more than 6 weeks wool cover, continued to show significant differences in the incidence and severity of fleece-rot dermatitis. To test the hypothesis that these sheep might also exhibit differences in their local skin reactions and immune responsiveness, 3 intradermal injections of killed Pseudomonas aeruginosa were administered at monthly intervals. After primary intradermal challenge, R sheep had a higher incidence of skin induration and a stronger inflammatory response (increased induration diameter) than S sheep. Compared to S sheep, R sheep also developed higher levels of circulating antibodies against whole cell antigen and both inner and outer membrane proteins of P. aeruginosa. These responses were maintained in R sheep with each consecutive challenge while S sheep showed a decline in their immune responsiveness. Differences in antibody response against outer membrane proteins were also detected when antigenically naive sheep from each genetic line were sensitised by epicutaneous challenge with P. aeruginosa under experimental wetting conditions. Intradermal challenge of these animals 6 months later with outer membrane proteins, revealed a late maximum (72 h) in the development of induration diameters for R sheep while S animals showed maximal induration diameters by 24 h. However, there was no significant difference in induration response between 24 h and 72 h within each group of sheep.(ABSTRACT TRUNCATED AT 250 WORDS)     

Evaluating a novel analgesic strategy for ring castration of ram lambs

Objective To evaluate the analgesic efficacy of the NSAIDs flunixin and meloxicam administered locally to the scrotum before ring castration. Study design Randomised, controlled, prospective study. Animals Forty eight single born male Merino lambs. Methods Lambs, aged approximately 4 weeks, were allocated to four groups for castration. Groups were: sham control; castration + saline; castration + flunixin; castration + meloxicam. Drugs (5 mL) were administered subcutaneously around the circumference of the scrotum immediately before castration. Cortisol, rectal temperature, haematology and plasma haptoglobin were measured before and up to 48 hours after treatment. Behaviour recorded by video for 12 hours after treatment was classified as pain avoidance behaviours in the first hour and postural behaviours in three 4 hour intervals. Results Ring castration (saline group) induced a bi‐phasic increase in cortisol with peaks at 90 minutes and 24 hours but no significant changes in haematology, haptoglobin or rectal temperature. Pain avoidance behaviours were increased and teat seeking decreased. Normal lying and normal standing postures were decreased and abnormal ventral lying, statue standing, abnormal standing and total abnormal postures increased. Flunixin decreased cortisol at 90 minutes (60.3 versus 117.3 nmol L^?1) and cortisol AUC (0–6 hours), decreased elevated leg movement (2.5 versus 5.4 events) and sum of pain avoidance behaviours (8.5 versus 16.7 events), improved time spent in normal ventral lying and decreased abnormal ventral lying and total abnormal postures compared to saline treated lambs. In a similar contrast, meloxicam caused non‐significant decreases in cortisol at 90 minutes, cortisol AUC (0–6 hours) and pain avoidance behaviours, and significantly improved the postural behaviours normal ventral lying (26.7 versus 15.4%) and normal standing (13.9 versus 7.5%), and reduced abnormal standing and total abnormal postures. Physiological and behavioural responses associated with ring castration for both NSAID treatment groups were generally greater than sham controls. Conclusions and clinical relevance Locally administered NSAIDs provided partial analgesia for ring castration.     

Strategic use of crutching and dicyclanil to protect unmulesed sheep against breech strike

Objective   To test strategies for the application of dicyclanil and mid-season crutching to maximise protection of unmulesed sheep against breech strike.
Procedure   Three hundred and eighty unmulesed Merino weaners were randomly allocated to four groups either left untreated or treated by different strategies with 50 g/L dicyclanil. Treatments included breech treatment alone and breech plus body treatment, with two application times, immediately after shearing and 6 weeks after crutching or shearing. To assess protection, larval implants with newly hatched Lucilia cuprina larvae were applied to 10 different sheep from each group at 3, 4, 5 and 6 months after crutching and shearing and assessed for the development of strike at 48 hours. The concentration of dicyclanil was measured in wool samples clipped from the breeches of the test sheep.
Results   All dicyclanil treatments gave significant reduction in strike in comparison to controls up until 4 months after crutching but protection in the sheep treated immediately after shearing had waned at 5 months. Treating at 6 weeks after crutching provided significant reduction ( P < 0.05) in strike for 6 months. Results for strike incidence immediately after shearing and concentration of dicyclanil in the breech wool also suggested improvements in protection by delaying treatment for 6 weeks.
Conclusion   In most environments it should be possible to protect unmulesed sheep against breech strike with a carefully planned integrated control program incorporating strategically timed crutching, shearing and dicyclanil application. Delaying treatment with dicyclanil to at least 6 weeks after shearing or crutching increased the protection provided in comparison to treatment immediately after shearing.     

Effect of mulesing and shearing on the prevalence of effect of mulesing and shearing on the prevalence of Erysipelothrix rhusiopathiae arthritis in lambs

OBJECTIVE: To examine the effects of management practices and environment on the prevalence of arthritis in lambs. DESIGN AND POPULATION: A case-control study was conducted on groups of lambs from 122 Western Australian sheep flocks. METHOD: Arthritis was diagnosed by visual assessment of lambs at abattoirs by qualified meat inspectors. The prevalence was estimated from data collected from producers on culling practices for arthritis. Data on management practices and environmental variables were collected by personal interview. Stepwise logistic regression was used to measure the effects of the most important factors on the prevalence of arthritis. RESULTS: Mulesing and shearing lambs increased the odds of high prevalence of arthritis by 7 (95% CI 1.9 - 25.6) and 4.3 (95% CI 0.9 - 19.6) times, respectively compared to unmarked and unshorn lambs. Lambs slaughtered between December and June had 3.7 (95% CI 0.8 - 16.6) times greater odds of having a high prevalence of arthritis than lambs slaughtered in the remainder of the year. CONCLUSIONS: This study indicates that, to decrease the risk of high prevalence of arthritis, lambs raised for meat production should not be mulesed or shorn. Recommended improvements to hygiene at mulesing such as the use of portable yards had little effect on the prevalence of arthritis.     

Comparison of a liquid and a powder insecticidal dressing to aid healing and prevent flystrike of mulesing wounds in lambs

A proprietary insecticidal mulesing powder containing diazinon and an experimental liquid dressing based on eucalyptus oil, naphthalene, cresylic acid and chlorfenvinphos in a carrier of liquid hydrocarbons and petroleum oil were compared for their ability to promote wound healing and reduce the incidence of fly strike in freshly mulesed lambs. Throughout the trial period of 4 weeks, fly trapping confirmed the presence of Lucilia cuprina in the paddock where the ewes and lambs were grazing At inspection one month after mulesing, no deaths had occurred since mulesing and no lambs showed evidence of cutaneous myiasis, although a number of their dams (with 8 months wool) were struck. At 4 weeks after mulesing, the wounds of the lambs treated with the experimental liquid dressing showed better healing than those treated with the powder dressing. It was concluded that both mulesing preparations were effective in inhibiting flystrike, but the liquid dressing promoted faster wound healing than did the powder.     

A neurological locomotor disorder in sheep grazing Stachys arvensis

OBJECTIVE: To describe the clinical signs and pathology of a neurological locomotor disorder in sheep associated with ingestion of Stachys arvensis. DESIGN: Field observations and laboratory examinations. PROCEDURE: Clinical and pathological examinations were performed on sheep with suspected S arvensis intoxication. FIELD OBSERVATIONS: Merino sheep in a flock on the southwestern slopes of New South Wales developed a neurological disorder after grazing S arvensis. Affected animals had pelvic limb paresis and a proprioceptive deficit. When forced to exercise they stumbled and collapsed. Recovery following removal from the plant was slow. Many deaths were associated with the outbreak. RESULTS: Affected sheep developed a mild degenerative myelopathy and peripheral neuropathy. Deficiencies of vitamins A and E were also observed in the affected flock. CONCLUSION: Grazing S arvensis is sometimes associated with a neurological locomotor disorder in sheep.     

The use of an autogenous Dichelobacter nodosus vaccine to eliminate clinical signs of virulent footrot in a sheep flock in Bhutan

An outbreak of virulent footrot was investigated in a flock of 605 Merino cross-bred sheep in Bhutan. Conventional control methods in the preceding eight years had reduced its prevalence from 36-79% in different components of the flock to about 15% overall. Only one serogroup (B) of Dichelobacter nodosus was identified among 40 isolates cultured from affected sheep. A vaccine prepared from this strain was used in a pilot trial to compare the response of 14 treated and 14 untreated sheep. All affected, vaccinated animals in this trial healed quickly and were protected against re-infection while additional cases developed among untreated sheep during a period favourable for the spread of footrot. The serogroup B vaccine was administered to the whole flock for two successive years. No other footrot treatment was given during these or subsequent years. The whole flock was examined three times, foot by foot, for two years and twice yearly for another two years. When vaccination began there were 88 affected sheep in the flock, an affected sheep being defined as an animal with a foot-score of 2 or greater in one or more feet. There were neither affected sheep in the flock 30 days after the first dose of vaccine nor were any identified in later inspections. Virulent footrot, originating from the farm under investigation, persisted in neighbouring village flocks during this period. It was concluded that whole flock specific D. nodosus vaccination made a major contribution to the elimination of all clinical signs of footrot from the flock of 605 sheep where the condition had previously persisted for 10 years.     

Use of interpolated climatic parameters to predict risk of blowfly-strike in Queensland sheep flocks

The risk of blowfly-strike was investigated in 160 sheep flocks in Queensland, Australia. The association between blowfly-strike--measured by the use of pesticides in response to flystrike reported by flock managers during the period 1994-1997--and interpolated rainfall and temperature data was examined using survival analysis and stepwise regression. The statistical model explaining the most variation in risk of blowfly-strike included average maximum temperature and its second-order polynomial 4 months preceding flystrike. The model was validated using reports of blowfly-strike from 87 flocks during the period 1997-1999 (collected using the same method as for model construction) and interpolated maximum temperature data. Although there was overlap of 95% confidence intervals derived for model coefficients estimated using both construction and validation data sets, false-negative and false-positive misclassification percentages were 33.3 and 53.3%, respectively. False-negative misclassification was greater for flocks located in southern Queensland, and false-positive misclassification was greater for northern Queensland flocks.     

The impact of malnutrition and other causes of losses of adult sheep in 12 flocks during drought

OBJECTIVE: To establish the range and cost of losses in Merino flocks in southern New South Wales during drought conditions by determining the cause of death, morbidity or wasting in adult sheep. DESIGN AND POPULATION: Pathological studies were performed on 392 dead or moribund adult sheep from 12 Ovine Johne's disease (OJD)-infected flocks during 2002 and a further 58 sheep culled due to wasting from one of these flocks in 2003. Flocks ranged between 3,500 and 20,000 sheep. METHOD: The most likely cause of death, morbidity or wasting was determined following consideration of the environment in which the animal was found, clinical and gross pathological findings, plus histopathology of tissues collected during necropsy. RESULTS: A most likely cause of death, morbidity or wasting was determined for 362 sheep in 2002 and 58 sheep in 2003. OJD contributed to the death of 250 sheep in 2002, and wasting of 48 sheep in 2003. Of the sheep that died or were euthanased due to other causes, malnutrition was a contributing factor in the death of 70 sheep (63%) in 2002 and 2 sheep (20%) in 2003. Losses were not evenly distributed across flocks, with 57% of mortalities caused by malnutrition in 2002 occurring in one flock. Malnutrition accounted for 18% of the annual cost of all deaths among adult sheep in 2002 with an average cost of $16,882 per farm. Losses not attributed to malnutrition included a range of infectious and non-infectious disorders. These included balanoposthitis, clostridial enterotoxaemia, cutaneous myiasis, endoparasitism, enteritis, intestinal adenocarcinoma, misadventure, peritonitis, periparturient death of ewes, photosensitisation, pneumonia, post-shearing stress and squamous cell carcinoma of the perineum. CONCLUSION: Almost one third of mortalities in OJD-infected flocks during drought were unrelated to OJD and could be reduced by improving nutritional and disease management practices. The importance of close supervision of the flock is highlighted so that early management intervention can be instituted, including the culling of cases of welfare concern.