severe in some of these cases if the femoral head has not yet travelled around the acetabulum.

Differentiation of dislocation from fractures of the proximal femur is difficult based on palpation and manipulation alone, but in our experience, proximal fractures are rare, the joint being much more likely to give way than the femoral neck, greater trochanter or proximal femoral shaft. The fractures observed in this study would have occurred at the time of or following the dislocation, because in each case the femoral head was dislocated to the obturator foramen. The femoral neck of the dislocated femurs in all of the cases examined at the knackery had marked scalloping where it was in contact with the sharp rim of bone on the antero-lateral border of the obturator foramen. The wedge pressure between the fem- oral head lying inside the obturator foramen and the greater trochanter lying outside could be sufficient, particularly in cows repeatedly struggling to get up, to cause separation of these two structures.

‘Ability to stand’ appears to be the most useful prognostic factor, resulting in 6/47 (13%) errors in ability to predict outcome. Analyses including additional factors (after standing) were not able to decrease this. Cows that are able to stand with the dislocation would be expected to have a better prog- nosis. It indicates sufficient strength of limb remaining to raise themselves when the hip is in its correct position. Most failures are attributed to splaying of the limb laterally as the cow struggles to position its feet. Oth’er factors such as age and bodyweight may be confounded with ‘ability to stand’ and so influence the prognosis. For example, younger cows will have lower body weights and hence may find it easier to stand when one leg must take most of the weight. Additionally, the reduced use of the dislocated limb whilst trying to rise would

limit periarticular damage improving the chances of the hip remaining in place following reduction, The effect of ability to stand remained at least marginally significant (p < 0.1) when age, bodyweight, duration of dislocation and direction of dislocation were stratified (Table 3).

There was insufficient evidence (p = 0.15) to provide support for our belief, based on previous experience, that cows with calving paralysis or suffering ‘downer cow syndrome’ such as follows metabolic disease, have a much poorer prognosis, but there is a trend toward this belief.

Of special interest was the lack of influence of replacement time on the prognosis. It had been thought that the more difficult it was to reduce the dislocation, the less likely it was to redislocate.

The increased success associated with replacing hips within 12 h of dislocation is consistent with the finding of Larcombe and Malmo (1989). The negative effect of increasing time from dislocation to treatment may be due to increasing nerve and muscle damage with time. At autopsy there is often a large blood clot and torn bands of muscle and joint capsule within the acetabulum. This may prevent proper seating of the head of the femur following reduction if sufficient time has passed to allow organisation of the clot and torn tissue into a less displacable form.

References Bradley JV (1968) - Distribution-free Statistical Tests, Prentice-Hall,

Greenough PR, MacCallum FJ and Weaver A D (1981) - Lameness

Larcombe MT and Malmo J (1989) - Ausf Vet J (in press)

New Jersey, p 195

in Caftle 2nd edn, Lippincott, Philadelphia, p 269

(Accepted for publication 19 April 1989)

Evaluation of dressings to aid healing of mulesing wounds on sheep GW LEVOT, PB HUGHES and CJ KALDOR

Biological and Chemical Research Institute, NSW Agriculture and Fisheries, PMB 10. Rydalmere 21 16

SUMMARY: Five proprietary and one experimental dressing were compared with no treat- ment in their ability to aid healing of mulesing wounds in over 1900 young iambs. Healing was judged as the completeness of shrinkage of the mulesing cuts and the condition of scabs on the new skin surface. When assessed at 21 d it was found that treatment with Heriots Crown Wound PowdeP or Coopers Mulesing PowdeP offered a significant advan- tage over leaving the wounds untreated. Neither aqueous organophosphate washes, De- fiance@ nor Defiance@ containing 0.08% chlorfenvinphos offered any healing advantage over controls. However, washing the wounds with an aqueous organophosphate solution aided healing more than the Defiance@-based dressings. it was considered that the powders or the washes encouraged quick scab formation either by creating a dry covering (powders) or by washing away blood and allowing fast drying of the wound. The Defiance@-type dressings slowed healing by keeping the wound moist for up to 10 d, but healing was not significantly different to the untreated group by 21 d. Aust Vet J 6 6 358-361

Introduction There is no doubt that the Mules operation, especially when

combined with correct tail length, provides permanent, effec- tive protection from crutch strike. There has been con- siderable controversy, however, regarding the necessity or desirability of dressing the cut area. Mackerras (1935) con- sidered a mildly antiseptic dressing might assist healing and prevent flystrike but insisted that irritant fly dressings would be harmful. By 1943 the CSIR and the New South Wales Department of Agriculture were recommending leaving the wounds untreated (Anon 1943). They stated that the cut edges started to come together in 2 to 3 d and that healing, unless disturbed by bushfly irritation, was usually complete in 3

358

weeks. Mulesing while bushflies were active was discouraged. However, if flystrike became a problem treatment of the wound with 5% aqueous solution of copper sulphate was recommended for its drying effect on the wound (Anon 1943). Johnstone (195 1) believed an efficient dressing should prevent oviposition on or around the wound and exert minimal in- terference with healing. No larvicide was needed under ideal conditions, but if healing was incomplete by the time repellen- cy was lost, some protection against the development of eggs or larvae was desirable. Field testing of dressings indicated that Ceylon oil of citronella was the most efficient repellent (Johnstone 1951) but dibutyl phthalate was also acceptable when applied liberally (Johnstone and Southcott 1954). Reid

Australian Veterinary Journal, Vol. 66, No. I I , November, 1989

(1952) stated that dressings should be used only if flystrike had been present before the operation.

More recently it has become common practice to dress wounds with a diazinon powder or to wet the breech area with a jetting fluid (Baillie 1979) before or after mulesing. At least 9 proprietary dressings are available (although not in all States) for the treatment of mulesing wounds. Most of these contain an organophosphorus insecticide (OP) and their manufac- turers claim they provide some degree of protection from flystrike. However, little is known of the relative abilities of these products to aid wound healing and prevent flystrike.

This report presents data on the ability of available treatments to facilitate healing of mulesing wounds in lambs.

Materials and Methods General

Lambs used were from the spring drop at the Agricultural Research Centre, Trangie. The mulesing operation was per- formed with razor-sharp mulesing shears while the lambs were held in a 5-berth mulesing cradle. Skin on the tails was strip- ped to leave a vee shaped piece of wooly skin above. Tails were docked with a cauterising knife. The dressings were applied as recommended by the manufacturers and the lambs released feet-first onto the ground to "mother-up".

Sub-trial I This experiment examined potential differences between

powder and liquid dressings in aiding healing; 1,538 lambs were divided into 6 approximately equal groups and, after be- ing mulesed, were treated as follows: 1 . Powder dressing (non-insecticidal); Heriots@ Crown

Wound Powder* 2. Powder dressing (insecticidal); Coopers" mulesing

powder5 3. Liquid dressing (non-aqueous); Shell Defiance@ livestock

dressing7 4. Liquid dressing (non-aqueous); Shell Defiance@ + C (De-

fiance + 0.08% ch1orfenvinphos)t 5. Liquid dressing (aqueous); Topclip@ Blue-label diazinon

wash (0.04%)$ 6. Untreated

These groups were inspected 21 days after treatment and scored for wound healing and fly-strike prevalence.

Scoring of healing was based on how much shrinkage had occurred to the mulesed area, and the degree of scabbiness. The more complete the shrinkage, the lower the score on a 1 to 3 basis (Figure 1 ) . Fast healing of the tail was important. Once the scab had fallen to reveal intact skin the likelihood of the wound being opened up by being knocked on fences or nudged by the mother was reduced. Although the scabbiness score was based mainly on the appearance of the tail, it was noted that the scabs on the mulesing wound, if not fully shrunken, were usually similar to those on the tail. The scheme used was: I . Completely healed, healthy new skin visible; 2. Healing well, but skin not tough enough to prevent damage

3. Thick scabs; 4. Very scabby, very easily damaged, or already damaged; or 5 . Very poor healing, red-raw or still bleeding.

Score categories were grouped into healing classes as follows: very good (1.1, 1.2); reasonable (2.1, 2.2, 3.1, 3.2, 1.3); poor (2.3,2.4, 1.4, 1 .5) and very poor (2.5,3.3,3.4,3.5), where the first digit is the wound shrinkage score. Differences

if knocked badly;

Heriot Agvet Pty Ltd, PO Box 302, Ferntree Gully, Victoria 3156

t Shell Chemical A u s t Pty Ltd, 155 William Street, Melbourne, Victoria 3000; The formulation of Defiance@ has been altered to reduce its viscosity since this trial was completed.

$ Ciba-Geigy Aust Ltd, Pendle Hill , New South Wales 2145 3 Coopers Animal Health Aust Ltd, PMB PO Bringelly, New

South Wales 2171

Australian Veterinary Journal, Vol. 66, No. 11, November, 1989

1

1 U

Figure 1. Mulesing wound shrinkage scores for sub-trials 1 and 2.

between treatments were analysed using a multi-nominal model fitted by iterative weighted least squares (Bock 1975).

Sub-trial 2 The wound healing properties of liquid dressings were

assessed in this sub-trial. 304 lambs were mulesed, divided into approximately equal sized groups and treated as follows: 1. Untreated 2. Defiance@ livestock dressing 3. Defiance@ + C 4. Supona@ aqueous wash (chlorfenvinphos 0.08Vo)

cording to the scheme detailed above. Lambs were assessed 21 d after mulesing. Scoring was ac-

Sub-trial 3 Six groups of 10 lambs were mulesed and treated as in sub-

trial 1. These were kept in small paddocks and brought into holding pens about every second day for inspection. In- evitably, some damage to scab formation occurred with fre- quent handling. However, the first few inspections indicated which treatments aided early wound healing.

Results Weather conditions at Trangie were cool and bushflies did

not irritate wounds to any significant degree. Flystrike prevalence in the Agricultural Research Centre flocks at Trangie was low, those that did occur were mostly in ewes with lambing stains. Only 2 of the 1,902 lambs were fly blown and no lambs died.

Sub-trial I There were no significant differences in the spread of heal-

ing scores between the 2 powder treatments, nor between the 2 Defiance@-based products (Table 1). However, healing scores for pow+prs were better than controls, that is, untreated wounds ole 1). None of the liquid products (Topclip" wash, Defi,nce@, Defiance@ + C) offered any healing advan- tage over leaving the wound untreated. In fact, Defiance@

359

TABLE 1 Frequency (YO) of heallng categories after dressing mulesing

wounds in lambs using 6 treatments (sub-trial 1)

Amount (9) Healing categories of dressing

Treatment perlamb VG R P VP

Control - 11.1 37.3 33.2 18.4 (N =217)' ' Topclip" Wash 24.5 14.1 38.3 36.3 11.3 (N =248) ' Defiance" 12.1 7.1 35.1 34.3 23.5 (N = 268) Defiance@ + C 14.2 6.4 38.3 37.9 17.4 (N = 235) ' Coopers Mulesing PoweP 8.8 16.5 40.3 31.9 11.4 (N = 273) Heriots Crown Wound 2.2 17.8 38.4 33.0 10.8 Powder@ IN = 297)

VG very good R Reasonable P Poor VP Very Poor N number of lambs At t h e 5% level of significance, a significantly better than con- trols, ' not significantly different from controls, ' significantly worse than controls

TABLE 2 Frequency ( O h ) of healing categories after dressing mulesing

wounds in lambs using 4 treatments (sub-trial 2)

Treatment Healing rating

VG R P VP

Control 1.4 37.5 22.2 38.9 (undressed) (N =77) ' Suponam Wash 5.1 51.3 24.4 19.2 (N = 72) a

Defiance" 1.3 42.9 20.8 35.1 (N = 78) ' Defiance" + C 0 39.0 27.3 33.8 (N = 77) ' VG very good R Reasonable P Poor VP Very Poor N number of lambs At the 5% level of significance, a significantly better than con- trols, ' not significantly different from controls.

treatment produced significantly worse healing scores than found in controls. Healing scores for the diazinon wash treat- ment group were significantly better than for the Defiance@ or Defiance@ + C groups but were no different to controls. There was a significant advantage in using a powder dressing rather than either of the Defiance@-based products.

Sub-trial 2 Analysis of the distribution of healing scores of lambs in

sub-trial 2 indicated that there were no significant differences between the Defiance@-based products and the controls. There was, however, a significant advantage in using the Supona@ wash rather than the Defiance@-based dressings or leaving the wound untreated (Table 2).

Sub-trial 3 Thick blood stains were obvious on control lambs one day

after treatment. The Topclip" wash and the Defiance@-based treatments produced apparently cleaner wounds, but Heriots Crown Wound Powdef made a complete covering of the wound, preventing bleeding and thereby drying out the wound. At 3 days after treatment the lambs treated with Coopers Mulesing PowdeP had dry scabs forming, but, unlike the Heriots Crown Wound Powdef, the Coopers@ powder was not visible on the wounds. Defiance@ and De- fiance@ + C treated lambs formed moist scabs.

By 7 d after treatment damage caused by handling for in- spection was evident on lambs in all groups. Scabs on the lambs dressed with either Heriots Crown Wound Powder@,

360

Coopers Mulesing Powder", Topclip Wash@ or left untreated were usually described as thick and crusty; lambs dressed with Crown Wound Powder@ having a continuous scab across the wound. The DefiancCand Defiance" + C treated lambs had thinner scabs than the other treatments.

Shrinkage of the mulesing wound was evident by 10 d after treatment. The Defiance@ and Defiance@ + C treated lambs still had the thinnest scabs, but, from this time on, shrinkage of the mulesing wounds continued at a similar rate in all treat- ment groups. In those lambs whose tails had not been damag- ed, the skin around the tail had begun to shrink noticeably.

Discussion The results for this trial were collected in the absence of

bushflies or high blowfly numbers. There is no doubt that ir- ritation to wounds by bushflies during the first day or so after mulesing prevents the initial sealing of the wounds and makes lambs more vulnerable to flystrike. Clearly, the quicker the cuts heal the less opportunity flies have to strike the wounds.

A range of healing scores was found within each treatment group. The dressing ranked best had a proportion of scores in the poor and very poor categories and the treatment ranked worst had some scores in the very good class. However, there were significant differences overall in the distribution of scores between treatments and controls. This indicates that certain dressings are more likely to facilitate healing than others.

The powder treatments were superior to the other dressings in promoting wound healing, and considerably less of these were applied to the mulesing wounds (Table 1). It is likely that a dry film over the wound aids shrinkage and thus facilitates healing. Heriots Crown Wound Powder@ formed a continuous coverage over the wound area, thereby sealing it, and remain- ed obvious on the cut area longest. Defiance' and Defiance@ + C kept the area moist longer, thereby delaying shrinkage and subsequent healing relative to the powder treatment. In both sub-trials 1 and 2 the organophosphate washes (Topclip@ and Supona@) offered an advantage over either Defiance@ or Defiance@ + C. In sub-trial 1, however, Topclip@ performed no differently to the controls.

The two powders and the organophosphate washes would have epcouraged quick scab formation, either because of a dry covering being formed by the powder or by the faster drying of the area following the washing off of blood from the wound. It was noticed (sub-trial 3) that the Defiance@ and De- fiance@ + C, at least while still present on the wound, delayed scab formation. This delay may explain the higher proportion of "poor" and "very poor" scores, as less time had been available since the drying of the wound, for scabs to fall and healing to be completed. It should be noted, however, that in either sub-trial 1 or 2, the results for the controls and the Defiance-based treatment groups were not significantly dif- ferent when assessed at 21 d after treatment.

Good farm management will minimise the opportunity for bushflies or blowflies to irritate wounds by mulesing at fly- free times. Not only does this avoid problems with flystrike and healing delays, but also eliminates the transmission of eperythrozoonosis (E. ovis) by bushflies. Despite these advan- tages, mulesing is sometimes done when flies are active. Under these conditions an insecticidal or strongly repellent dressing such as Defiance@ would be appropriate. However, when flies are not present, powder treatments are more advantageous by promoting wound healing within the first 10 d after mulesing.

Acknowledgments The mulesing expertise of Mr S Semple, Technical Officer (Scien-

tific). and the assistance of the farm staff at the Agricultural Research Centre, Trangie, are greatly appreciated.

We thank Shell (Aust Pty Ltd) and the Wool Research and Develop ment Fund for their financial support.

References Anon (1943)-Recent advances in the prevention and treatment OJ

blowfly strike in sheep Suppl to Report No. 2, Joint Blowfly Com- mittee, Department of Agriculture, New South Wales

Awtmiian Veterinary Journal, Vol. 66, No. 11, November, 1989

Baillie BG (1979)-Managementpractices for controllingflystrike Na- tional Symposium on the Sheep Blowfly and Flystrike in Sheep, Sydney, June 1979, p 159

Bock RD (1975)-Multivariafe Statistical Methods in Behavioural Research, McGraw-Hill. New York

Johnstone IL (195 1)-Aust Vet J 27: 53 Johnstone IL and Southcott WH (1954)-Aust Vet J30: 139 Mackerras IM (1935)-J Council Sci Ind Res 8: 169 Reid ws (1952)-J Dept 56: 220

(Accepted for publication 17 May 1989)

Nutritional myopathy in goats AD ROSS*, CG GEEt, ARB JACKSONS, E HALL4 and PL GREENTREE!

SUMMARY: A nutritional myopathy in unweaned fibre goats aged 2 to 4 mths is described in 3 flocks from the tablelands of New South Wales. Clinically affected animals were illthrifty and in circulatory failure prior to being found dead. At necropsy, there was pronounced ascites, pulmonary congestion and marked mottling of the liver. Chalky white streaks and patches were obvious in the myocardium, particularly in the right ventricular wall. Skeletal muscles varied from grossly normal to generally pale. Histologically, the myocardium ex- hibited areas of severe acute myonecrosis with mineralisation and adjoining areas of phagocytosis and fibrosis. In 2 of 3 flocks, some skeletal muscles showed a mild subacute myopathy. Marked hepatic congestion extended to periacinar haemorrhage and necrosis in some areas. Dietary imbalances of selenium, vitamin E and polyunsatured fatty acids were probable factors in the pathogenesis of the condition. Aust Vet J 6 6 361-363

Introduction Nutritional myopathy is well known as a clinical entity in

unweaned sheep and cattle in Australia (Blood et a/ 1983). Lambs and calves 2 to 4 months old, grazing highly productive improved pastures are most frequently affected. In New South Wales, acute or subacute skeletal myodegeneration can occur in newborn lambs but is more commonly seen in lambs up to 3 months of age (Plant 1985). In calves, sudden death associated with acute myocardial degeneration and necrosis is the most common syndrome which may be accompanied by skeletal myodegeneration.

Nutritional myopathy has been reported in goats in New Zealand (Ross 1984; Thompson 1987a), USA (Guss 1977), Switzerland (Tontis 1984) and Turkey (Baram 1966) but ap- parently not in Australia. This report describes the Occurrence of nutritional myopathy in 3 flocks of goats on the tablelands of New South Wales.

Materials and Methods History of Flocks

Flock 1 consisted of 670 Angora does in an area of yellow podsolic and solodic soils 29 km east of Goulburn on the southern tablelands, with an annual average rainfall of 700 mm. The pastures had been dressed with 125 kg/ha of super- phosphate annually for the previous 6 years. Throughout pregnancy and lactation the flock grazed improved pastures of ryegrass, subclover and native grasses with a small supplement of hay in late winter. By December 1985, 50 of 230 unweaned kids aged 3 to 4 months had died and a further 50 were in poor condition, with ascites and diarrhoea although spring pastures were abundant. No selenium or vitamin E supplements had been given.

Flock 2 comprised a Feral x Cashmere flock of 400 does run on yellow podsolic soils at Hillgrove 25 km east of Armidale with an annual average rainfall of 850 mm. The pastures were

NSW Agriculture 8 Fisheries, Regional Veterinary

t Pastures Protection Board, PO Box 67, Goulburn, New South

$ NSW Agriculture 8 Fisheries, Regional Veterinary

Q NSW Agriculture 8 Fisheries, PO Box 99, Armidale, New

1 Pastures Protection Board, PO Box 115, Tenterfield, New

Australian Veterinary Journal. Vol. 66, No. 1 1 , November, 1989

Laboratory, Glenfield, New South Wales 2167.

Wales 2580

Laboratory, Armidale, New South Wales 2351

South Wales 2350

South Wales 2372

native grasses with some clovers and medics and had been oc- casionally top dressed with superphosphate. Pastures were drought affected until the does were in late pregnancy when heavy rains provided good spring pasture growth. Sheep were run on the farm and given selenium supplementation as is nor- mal practice in the area but the goats were not. In October 1983, a group of 80 does and 50 two to three week old kids were examined. Four kids had died, another 5 were in poor condition and depressed and approximately 25 had diarrhoea.

Flock 3 was a small Feral x Angora flock of 60 does at Tenterfield on the northern tablelands run on yellow sodolic soils with yellow podsolic intersperse. The average annual rainfall was 800 mm but 1980 was a dry year and pastures were drought affected. Throughout pregnancy and lactation, the goats grazed pastures consisting of tall fescue, ryegrass, paspalum, subclover and white clover. Approximately 125 kg/ha of superphosphate had been applied to the pastures in each of the previous 3 years. A soil test in 1980 indicated low levels of copper. The flock received supplements of locally grown lucerne and oaten hay together with cracked corn pur- chased from a stock feed merchant which contained a multivitamin and mineral supplement including unknown amounts of vitamin E and selenium. In August 1980, a 2-month-old male kid was found dead in a paddock where ap- proximately 20 weaner goats had died of unknown causes the previous autumn.

Histopathology and Biochemistry Selected samples of heart, skeletal muscles, liver, kidney

and lung were fixed in neutral buffered formal saline, routine- ly sectioned and stained with haematoxylin and eosin or Masson’s trichrome stain for histological examination. In 2 flocks samples of liver were stored frozen and assayed for selenium using the method of Bayfield and Romalis (1985).

Gross Pathology Flocks were examined clinically and a dead kid from each

flock was subjected to detailed post-mortem examination within 3 hours of death. Pathological findings were similar in all 3 goats. Kids were 2 to 4 months of age, thin with enlarge- ment of the abdomen. Body weights of 2 kids were 4.4 and 4.5 kg, indicating poor growth rates.

Straw coloured watery fluid was present in large amounts in all body cavities with 500 ml in the abdominal cavity of one kid. The livers were dark reddish purple, markedly congested with occasional ecchymotic haemorrhages under the capsule.

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