TABLE 1 Faecal egg count (FEC) and worm burdens in deer slaughtered at different times after treatment with 3.8 mglkg albendazole orally

Days Abomasal Parasite species and site found Deer post FEC worm No. treatment (epg) count Abomasum Tracheallung Caecumllarge intestine

1 7 120 1000 S. asymmetrica D. viviparus

2 never 160 2000 S. asymrnetrica D. viviparus Richuris sp

3 15 380 2800 S. asymmetrica D. viviparus Richuris sp

4 21 80 1000 S. asymmetrica D. viviparus

0. ostertagi

treated S. kolchida 0. venulosum 0. ostertagi

0. ostertagi 0. venulosum

0. ostertagi H. contortus

TABLE 2 Mean faecal egg count (FEC), FEC reduction % and 95% confidenc&intervals on day 13 following treatment with albendazole and ivermectin

Treatment (day 0) n

95% Confidence Intervals day 13 FEC (epg) reduction 010 Upper CI Lower CI

Control 9 120 f 105 3.8 mglkg albendazole 11 166 f 174 7.5 mglkg albendazole 11 128 f 137 0.2 mglkg ivermectin 11 68 f 102

0 0 43

44 57 87

0 0 0

deer did not receive treatment. In the other 3 groups, each of 1 1 deer were given either 3.8 mg/kg albendazole, 7.5 mg/kg albendazole or 0.2 mg/kg ivermectint orally. Thirteen days after treatment, a second faecal sample was collected and examined for nematode eggs.

Based on faecal sample reduction percentages, albendazole at either 3.8 mg/kg or 7.5 mg/kg did not reduce egg output in these deer, while ivermectin (0.2 mg/kg) reduced egg output by 43%. The 95% confidence intervals were 0 to 44, 0 t o 57 and 0 to 87 for 3.8 mg/kg albendazole, 7.5 mg/kg albendazole and 0.2 mg/kg ivermectin treated groups, respectively (Table 2).

All deer were subsequently treated on day 13 with 1 ml avermectint s/c. Two deer were slaughtered 47 d after avermectin treatment for worm counts. Both deer contained worms and gross pathological changes in the abomasal mucosa. Deer 1, which had been in the ivermectin group, had a FEC of 360,80, 0 and 0 epg at 13, 26, 53 and 60 d after initial treatment. Mild hyperaemia of the abomasal mucosa and an abomasal count of 100 S. asymmetrica and 5 Trichuris spp in the proximal colon was recorded. Deer 2 , which had been treated initially with 7.5 mg/kg albendazole, had a FEC of 0, 120,O and 0 epg on days 13, 26, 53 and 60 after initial treatment. The worm count from the abomasum was 4500: 86% S. asymmetrica and 14% 0. ostertagi. The mucosa of the abomasum was hyperaemic, oedematous and thickened, particularly in the pyloric region. No D. viviparus were detected in the lungs or faeces of either deer. The presence of worm eggs in faeces at day 13 in the FECRT test indicated that the treatments failed to totally eliminate the infection. The presence of worms in the 2 weaners necropsied 47 d after a second treatment was probably due to re-infection. However, negative egg counts in the latter 2 deer, 53 and 60 d after initial treatment suggests that suppression of egg production may also have occurred.

Failure of the anthelmintic treatments in these deer could be due to a number of factors such as insufficient dose, poor absorption of the drugs, or parasite resistance. Results from 2 studies in red deer (Mackintosh et at 1985; Watson and Manley 1985) suggested that deer are able to metabolise and excrete benzimidazole compounds more quickly than sheep and cattle. Poor efficacy of injectable ivermectin in red deer hinds has also been reported (Andrews and Lancaster 1988). The optimal dose rates in deer may, therefore, be higher than those recommended for sheep and cattle. Factors such as abomasal pH, oesophageal groove function, malnutrition and worm burden have been

Ivomec Liquid for Sheep@, MSD AgVet, Granville, New South Wales 2142

1 Avornec Antiparasitic Injection for Cattle@, MSD AgVet, Granville, New South Wales 2142

identified in sheep as factors which may affect the absorption and efficacy of anthelmintics (Marriner and Bogan 1981; Prit- chard 1980). Such factors may also affect the efficacy of anthel- mintics in deer.

References Andrews SJ and Lancaster MB (1988) - Vet Rec 123: 354 Bockeler W and Segebade R (1977) - Tierarzt Umsch 32: 473 English AW (1985) - In Biology of Deer Production, edited by Fennessy

P F and Drew KR, Royal Society of New Zealand, Wellington, Bulletin 22: 93

Enigk von K and Dey-Hazra A (1976) - Kleint Prax 21: 133 Georgi JR (1974) - In Parasitology for Veterinarians, 2nd edition, WB

Kalivoda J and Chroust K (1971) - Acta Vet Brno 40: 453 Mackintosh CG, Mason PC, Manley T, Baker K and Littlejohn R (1985)

Marriner SE and Bogan JA (1981) - Am J Vet Res 42: 1143 Presidente PJA (1979a) - Deer Refresher Course, University of Sydney

Post-graduate Committee in Veterinary Science, Proceedings No 49, p235

Presidente P J A (1979b) - In DeerFarming in Victoria Agnotes No 15, Department of Agriculture and Rural Affairs, Melbourne

Presidente PJA (1984) - Deer Refresher Course, University of Sydney Post-graduate Committee in Veterinary Science, Proceedings 72, p623

Presidente PJA (1988) - In Kendall Hall Seminars for Veterinarians, Recent Advances Series: Farmed Deer No. 31: 25

Prichard PK (1980) - In The Host Invader Inierpiay, edited by Van den Bossche H, Elsevier North-Holland Biomedical, Amsterdam, p73 1

Watson TJ and Manley TR (1985) - Res Vet Sci 38: 231 (Accepted for publication 12 September 1990)

Saunders, Philadelphia

- NZ Vet J 33: 127

Neck wattles in lambs Department of Agriculture and Rural Affairs, Regional Veterinary Laboratory, PO Box 388, Benalla, Victoria 3672

MJ LANCASTER

Department of Agriculture and Rural Affairs, PO Box 862, Shepparton, Victoria 3630

WD MEDWELL

Neck wattles are common in goats and occur occasionally in pigs. They are seen rarely in sheep (Ellenberger and Guenther 1908). Goat wattles usually occur at the external orifice of the third branchial cleft of the embryo (Davies 1920), and sheep

Australian Veterinary Journal, Vol. 68, No. 2, February, 1991 I 5

An outbreak of seborrhoeic dermatitis (greasy heel) in cattle

Department of Farm Animal Medicine

University of Queensland, PO Box 125, Kenmore, Queensland 4069

MW McLENNAN and Production, RCW DANIEL

We report an outbreak of seborrhoeic dermatitis (greasy heel, mud fever) that affected 100 of 190 lactating cows in a dairy herd with the first cases occurring 7 d after a period of heavy rainfall (500 mm in 6 d).

At the time of the outbreak the herd was grazing kikuyu pasture and received grain twice a day in feedstalls, after milking. The cows walked approximately 2 km twice a day to be milked and were watered from troughs located about halfway between the milking shed and the pasture. They also had access to hayracks and molasses troughs in this area and tended to congregate at the site after each milking. During and after the period of heavy rain, the walkways and area around the troughs became very muddy and cows frequently were observed by the herdsman to be standing up to their hocks in mud.

At the beginning of the outbreak, about 12 cows showed moderate lameness associated with swelling of the pastern area of one or both hind legs. Closer inspection revealed deep fissuring of the plantar aspect of the pastern area and an accumulation of moist exudate in these fissures (Figure 1). Over the next 2 w,

Figure 1. Longitudinal sections of an excised neck Wattle from a lamb.

wattles are probably analogous structures of branchial arch origin. While New Zealand shearers find and remove neck wattles occasionally in Dorset Down sheep, and less commonly in other breeds (N Johnson personal communication), there appears to be no record of these structures occurring in Australian sheep. This report describes a low prevalence of neck wattles in lambs from Merino ewes in 4 consecutive years.

A line of 450 young Merino ewes was purchased and run with Border Leicester rams and other Merino ewes as a single flock on a farm in north-eastern Victoria. In 1986, 270 lambs were marked from these ewes. Two ewe lambs and 1 ram lamb were noticed to have a pair of neck wattles. Two or 3 similarly affected Iambs were born in 1987, 1988 and 1989. The parents of affected lambs were not identified, but wattles were restricted to progeny of the one line of Merino ewes.

Each wattle was a tubular projection, approximately 3 cm long and 1 cm in diameter, located several centimetres caudoventral to the angle of the jaw. The sides were well covered in hair, while the tip was sparsely haired and greasy (Figure 1). Histologically, the wattles were epidermal-covered cores of loose connective tissue. Hair follicles, sweat glands and sebaceous glands were present on the sides. The number of hair follicles and sweat glands decreased towards the tip, leaving only sebaceous glands and an occasional hair follicle at the centre of the tip. In comparison, wattles obtained from a wether goat of feral origin were longer, narrower and evenly haired. Each goat wattle had a cartilage core surrounded by adipose tissue, and contained striated muscle. These differences are consistent with the findings of Ellenberger and Guenther (1908).

While Lush (1926) observed too few wattles in Karakul sheep to determine their mode of inheritance, he did conclude that such structures in goats and swine were inherited as a simple Mendelian dominant trait. If the same applies in sheep, then our observations are consistent with the carrying of the wattle gene by the particular line of Merino ewes rather than by the Border Leciester rams. No neck wattles were seen in any of the ewes but such structures would have been removed at first shearing, if present. The technical assistance of Miss J Sleep is gratefully acknowledged.

approximately 100 cows developed similar lesions. There were no age, breed, or time of calving effects observed in any of these cows. The more severely affected showed swelling from the coronet to the hock region in the hind limbs, and in addition to flexural fissuring in the pastern area, developed small fissures and scabs on the plantar aspect of the fetlock joint. Thickening of the skin in the pastern area was evident in most cows and some cows exhibited a moist exudative area (greasiness) from the bulb of the heel to the fetlock. Some cows also developed fissures on the volar aspect of the pastern area in one or both fore limbs. These lesions were associated with a moderate elevation in rectal temperature (39.5 to 39.8 "C) in a number of cows. In individual cows, lesions persisted for about 2 to 3 w and the outbreak persisted for approximately 6 w. During the first 3 to 4 w before effective control measures were developed, the herd milk produc- tion declined by 20%.

From swabs taken from fissures in the pastern area of 7 cows on 2 occasions, both aerobic and anaerobic bacteria were isolated. The aerobes included Micrococcus sp, corynebacteria and a -streptococci, while the anaerobes included Fusobacterium sp, Bacteroides melaninogenicus, Clostridiutn tetani and anaerobic streptococci. All isolates were sensitive in vitro to oxytetracycline, all but one were sensitive to penicillin and all were resistant to streptomycin.

In the initial stages of the outbreak a variety of treatments was used, none of which proved effective, including parenteral injections of penicillin-streptomycin or oxytetracycline and hosing of severely affected legs, followed by spraying with potassium permanganate solution. Because of the apparent lack of response to antibiotic injections, and because the herdsman was concerned about the volume of milk discarded if antibiotics were used, only the most severely affected cows were treated with parenteral antibiotics (penicillin) and control was attempted by other means. Two cows with severe lesions were removed to a dry yard at the Large Animal Clinic of the University of Queensland, and were treated once with intramuscular penicillin and daily with a proprietary cetrimide and gentian violet spray* on the lesions. These cows improved promptly and recovered in 10 d.

Muddy areas around troughs and hayracks were fenced off and new gateways were made to provide the herd with dry access to pasture. In addition, a footbath was built in a laneway where the COWS emerged from the walk-through milking bails. It was

References Davies CJ (1920) - Goal Keepingfor Milk Production, Geo Newnes, UK, n77 I,' '

Ellenberger Wand Guenther G (1908) - HistologiederHuussaeugetiere,

Lush JL (1926) - J Hered 17: 73

constructed with a wire-mesh ramp to remove Some faeces and Paul Parey, Berlin, cited by Lush JL (1926) mud from the cows' feet before they entered the footbath. The

* Cetrigen Wound Aerosol@, Vasco Animal Health, Boronia, Victoria (Accepted for publication I October 1990)

76 Australian Veterinary Journal, Vol. 68, No. 2, February, 1991