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This article was published in 1949
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INSTITUTE OF INSPECTORS OF STOCK OF N.S.W. YEAR BOOK.
COLIBACILLOSIS IN SHEEP
The Case History of a Probable Outbreak
D. J. WALKER B V.Sc., Inspector of Stock, Armidale.
Coliform orgnnisms are common inhabitants of the alimentary tract. According to Gaiger and Davies (1932) B. coli may become pathogenic and cause such conditions as cystitis and urethritis in sheep; abortion in mares, cows and ewes; white scours in calves and other infections. The same authority states that the organisms may penetrate the wall of the bowel and grow in the peritoneal fluid several hours before death.
In addition to the widely differing types of disease conditions which the organism may set up it is a common contaminant of material submitted for laboratory examination. Consequently caution must be exercised in attributing to it the cause of disease or death in unusual circumstances.
The history and finding in the mortality outlined are unusual and considered to warrant recording.
The report of the Director of Veterinary Research, Glenfield, upon specimens submitted was as follows:—
"The various smears submitted showed the presence of a few gram negative bacilli. Bacteriological examination of the pipettes resulted in the recovery of coliform organisms from the heart, liver bile and lymph gland. No growth was obtained from the kidney or spleen. There was no evidence of the presence of Salmonella organisms."
History. Some 550 fat four and six-tooth Merino wethers were involved. They were carrying fourteen months' wool and the fleeces were heavy. They were moved on the hoof from the property on which they are understood to have been bred some 70 miles to Walgett in N.S.W.; where they were held for 14 days in a paddock with ample good feed and water.
26th October, 1948. They were moved 230 miles by rail to Tamworth. According to the owner, the journey occupied 48 hours. The trip was described as "very hot."
28th October. They were untrucked and spelled for one day in the Tamworth sewerage Treatment Works paddocks. When placed in the paddocks they were very thirsty.
29th October. During the day they were taken to the Tamworth Sale yards and sold. They remained in the yards overnight.
30th October. They were removed from the saleyards, watered at the Peel River, loaded into trucks and taken to Armidale; a distance of 67 miles. They arrived at night, were unloaded and remained in the trucking yards for the remainder of the night in heavy rain.
31st October. At 6 a.m., in heavy rain, they commenced the 12 mile trip to the owner's holding, again travelling on the hoof. The travelling stock route was in good order for feed and water. When the journey was commenced one was dead in the yards and six were sick.
1st November. They arrived at their destination in the late afternoon, when approximately 20 per cent. of them were found to be fly struck. The same afternoon they were placed in good native pastures and ample water supplies.
Shearing Was commenced on the 4th November. On the 4th and 5th all sheep were held in the shearing shed, owing to heavy rain. During the whole period of shearing, which was completed on 12th November, all un-shorn sheep were held in the shed each night.
On the 16th November a visit was paid to the holding to investigate the mortality. Twenty-six had died.
Symptoms. Between 1 and 2 per cent. obviously had been losing condition rapidly; were tucked up and sluggish in their movements. These sheep possibly were afferted clinically; perhaps those which had been affected and were recovering. A later inspection indicated that they were developing the disease. Other than these, no sick sheep were observed personally.
The symptoms noted by the owner were a degree of lameness, sluggishness and excessive thirst. Affected sheep eventually went down. During late stages there was evidence of considerable pain. Deaths occurred from 12 hours to three days after the onset of the symptoms.
Post-mortem. A 6-tooth fat wether was available for port-mortem. It had been dead for between 20 and 30 minutes. The lesions noted were distended gall bladder, yellowish liver and congested kidneys. There was acute gastro-enteritis from the abomasum to the colon.
Further history. On the 23rd November another visit was paid to the property. No sheep were then sick. A further 24 head had died; the total loss being about 50 head. From the rate at which deaths had been occurring it was apparent that losses were at an end, or almost so.
Discussion. If, as is presumed, the basic cause of such a mortality is a reduction in resistrince due to exhaustion, it is difficult to understand why such outbreaks are not more common.
There is little doubt that the mob involved in the mortality outlined suffered the extremes of feast and famine, rest and exhaustion, and wide variations in heat and cold. In the absence of substantial proof that the handling was the essential cause of the trouble it merely is pointed out that such may have been the case.
Whatever else is involved, it can be maintained that excessive handling, resulting in starvation and exhaustion, is not in the best interest of any type of live stock.
Acknowledgement. The permission of the Director of Veterinary Research, Glenfield, to quote his report on the specimens submitted is appreciated and the assistance rendered by the Glenfield Research Station in this and similar matters is acknowledged.
Reference. Gaiger & Davies (1932)—"Veterinary Pathology and Bacteriology." Balliere, Tindall & Cox: London.