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This article was published in 1962
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INSTITUTE OF INSPECTORS OF STOCK OF N.S.W. YEAR BOOK.
Accidental Poisoning of Cattle with Lead Arsenate
J. M. WILSON, B.V.Sc., Veterinary Inspector, Casino
INTRODUCTION
The liver fluke (Fasciola hepatica) is endemic in most parts of the Far North Coast. Many farmers carry out routine drenching of cattle against this parasite during late summer and autumn. The drug commonly used in this area is hexachloroethane, and reports of mortalities in cattle following its use have been rare.
During March, 1960, a dairy farmer in the Casino District carried out routine drenching of his herd with a proprietary brand of hexachloroethane. A very heavy mortality ensued, but subsequent investigation indicated that the deaths resulted from accidental contamination of the drench during manufacture with lead arsenate. At about the same time, similar mortalities occurred in the Tweed-Lismore area from the same cause.
HISTORY
On the 22/3/60, following the afternoon milking, an owner in the Casino District drenched 25 Guernsey cows and one Guernsey with a proprietary brand of hexachloroethane. Drenching was carried out at the rate recommended on the manufacturer's label.
On the following morning it was seen that the milk production of the herd was extremely depressed, and that the cattle were showing a profuse, stinking, watery diarrhoea; and were very depressed. During that day, the cattle showed inco-ordination and exhibited symptoms of acute abdominal pain. Affected cattle finally went down, usually assuming a position of sternal recumbency with lateral deviation of the head and neck. This was followed shortly by complete prostration and death.
All 26 animals drenched had succumbed by mid-day on 24/3/60.
Similar mortalities occurred at about the same time in several herds in the Tweed-Lismore District; following use of the same proprietary brand of hexachloroethane. The same clinical picture was seen in each case, except that some of the Tweed-Lismore owners noted the presence of haematuria. This was not seen in the Casino herd.
TREATMENT
In several instances treatment of affected cattle was carried out by subcutaneous injection of 250 ml. of calcium borogluconate (40 per cent solution). Although this treatment resulted in some animals regaining their feet, relapses occurred in all cases; and the best that can be said for the treatment attempted was that it prolonged life.
Post-mortem
Post-mortem examinations were carried out on a large number of subjects, both in the Casino and the Tweed-Lismore areas.
Post-mortem findings were fairly constant and can be summarised as follows:—
Pallor of the conjuctivae, inflammation of the buccal mucosa, intense inflammation of the submucosal layer of the rumen, acute inflammation of the abomasal lining, and of the upper part of the small intestine. Inflammation was noted also in the lower part of the small intestine and in the large intestine. Livers were congested, kidneys injected, and some cases showed marked inflammation of the lining of the bladder.
RESULTS OF ANALYSIS
A wide range of liver samples and rumen contents were submitted to Glenfeld for examination for inorganic poisons. Analysis in the detection of both lead and arsenic in significant quantities. Results of analysis are given hereunder:—
| Tissue | Result |
|---|---|
| Liver (undried weight basis): | 10.1 - 30.9 parts per million of As203 |
| Rumen Contents (Undried Weight basis): | 91 - 124 ppm. of As203 |
| Rumen Contents (Undried Weight basis): | 80 - 198 ppm. of lead |
A sample of the drench also was submitted to analysis. Lead was found in gross amounts, but the quantity was not estimated. A sample of drench contained arsenic equivalent to 31.3 per cent of arsenie pentoxide. For comparison, a laboratory sample of lead arsenate analysed concurrently was found to contain 32.9 per cent of arsenie pentoxide.
DISCUSSION
From the results of analysis it appeared that the drench had been heavily contaminated with lead arsenate. Enquiries Indicated that one particular batch of drench was involved in all mortalities, and this batch was immediately withdrawn from sale. Further inquiries suggested that accidental contamination of the drench had taken place during the manufacturing process. Over 100 known deaths from this cause occurred in the Casino and Tweed-Lismore areas, but there is no doubt that several other mortalities occurred and were not reported.