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This article was published in 1960
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INSTITUTE OF INSPECTORS OF STOCK OF N.S.W. YEAR BOOK.
Lindane Poisoning in Calves
J. M. WILSON, B.V.Sc., Veterinary Inspector, Casino
Introduction
In October, 1959, an owner in the Casino District lost eight dairy calves as a result of suspected Lindane poisoning. This was confirmed by analysis of tissues.
History
The owner runs a small milking herd. Eleven Jersey and Jersey-cross calves, 2-3 months old, were seen to be moderately infested with lice, and slightly backward in condition. The owner's neighbour gave him a quantity of white powder, and suggested that he spray the calves at the rate of one ounce of the powder to one gallon of water. The owner made up a suspension of 8 ounces of the powder in 12 gallons of water, and sprayed the calves by means of a stirrup pump. Spraying was carried out late in the morning, and the calves were then confined in a small yard for one hour. The weather was warm and humid.
One hour after spraying the calves were turned into a paddock. It was noticed immediately that one of them was staggering; and on handling, began to take "fits". During the afternoon, several more calves were affected in a similar manner; while by nightfall, all but one were affected. During the night three calves died, and the owner sought veterinary advice the following morning. By this time a further calf thad died.
SYMPTOMS
All affected calves showed similar symptoms. Initial staggering was followed within a few minutes by profuse salivation with long strings of thick ropy saliva hanging from the mouth, Champing of the jaws and grinding of the teeth occurred; together with rapid blinking of the eyes. Trembling of various groups of muscles was followed by violent opisthotonic convulsions, occasionally with lateral deviation of the neck. These "fits" were accompanied frequently by agonised bellowing, which appeared to be initiated by auditory and sensory stimuli; for example, the barking of a dog or any attempt at manipulation. Fits lasted for up to half an hour, and when they had passed off the calves appeared exhausted and dopey, with apparently defective vision. Fits were likely to recur at any time, particularly as a result of external stimuli. Body temperatures were not recorded.
Post-mortem findings
Those consisted of congestion of the meningeal vessels, and the presence of excess cerebrospinal fluid; normal in appearance. The small intestine contained a small quantity of mayonnaise-like material.
Specimens of the brain, liver and kidney, together with some of the powder, were despatched to the Board of Tick Control, Lismore, for analysis.
TREATMENT
Intravenous injection of chloral hydrate solution was attempted, but found impossible to carry out because the stimulus of the needle initiated a convulsion. As an alternative, calves were given chloral hydrate by intra-rumenal injection. It was found that about 1-ounce of chloral hydrate was required to produce deep narcosis, which lasted for up to 5 hours.
Despite treatment, fits and mortalities continued until the third day, and a total of eight calves succumbed out of the eleven originally sprayed. Only one calf remained unaffected; this being the largest and strongest of the group.
ANALYSIS
Analysis of the powder revealed 19.4 per cent. BHC and 18.5 per cent. Gamma isomer; in other words the powder was "20 per cent. Lindane".
Analysis of the specimens revealed the following content of B.H.C.:—
Brain 20.0 mgms/kg.
Liver 22.0 mgms/kg.
Kidney 30.0 mgms/kg.
Discussion
Jolly and Kane found that the application of a 5 per cent. suspension of technical grade Benzene hexachloride to the skin of sheep produced no ill effects. It is known, however, that the toxic effects of BHC increase with the proportion of the gamma isomer present. In the case under discussion, the proportion of gamma isomer was 18.5 per cent. It is also probable that the warm weather increased the cutaneous absorption of drug.
Acknowledgement
The writer wishes to thank the Chairman, Board of Tick Control, for permission to publish analytical data.
References
Jolly, D. W. & Kane, G. J. (1950)—Vet. Rec. 62 : 377 - 379