In 1990 an outbreak of ataxia occurred in over 700 pigs in the north of England. Epidemiological studies demonstrated that the disorder was associated with the consumption of feed from a particular supplier and that one component (wheat screenings) was common to the batch of feed with which the ataxia was associated. An analysis of the feed demonstrated the presence of an organophosphorus pesticide, later identified as isofenphos, a pesticide not approved for use in the United Kingdom. The wheat screenings had been imported from France and the warehouse in which they had been stored was contaminated with isofenphos, which is approved for restricted use in France. Isofenphos is known to cause delayed neuropathy. The dose to which the pigs were theoretically exposed would be expected to have resulted in neuropathy (manifested as ataxia).

A case of sub-acute hydrocarbon poisoning of swans and several separate incidents of suspected chronic hydrocarbon poisoning of guillemots were investigated. The birds' tissues were saponified and extracted with pentane and analysed by gas chromatography-mass spectrometry. The residue levels of pristane in the swan tissues and aliphatic hydrocarbons in the guillemots' livers are reported and discussed.

This report summarizes the case histories and tabulates the analytical results from investigations of 8 incidents of suspected bromocyclen poisoning. Interpretation of the results and withdrawal of ALUGAN from the UK market are discussed.

A large number of passerine birds, mainly greenfinches, were found dead or dying in a hedgerow close to a field of onions recently sprayed with sodium monochloroacetate (SMCA). An analytical method is described for isolating monochloroacetic acid from bird tissues, as its potassium salt, by ion exchange chromatography. The ion exchange eluate is evaporated to dryness, acidified, extracted with ether and the ethereal extract methylated with diazomethane. The concentration of the methyl ester of monochloroacetic acid is determined using the Mass Selective Detector in the Selected ion mode. Chemical analysis confirmed the exposure of the birds to SMCA. It is calculated that 50 μl of spray contained the lethal dose of SMCA for a greenfinch.

A case of paraquat poisoning in a pack of foxhounds is reported. The incident provided a unique opportunity to compare residues levels of paraquat in dogs showing symptoms of acute and sub-acute poisoning. Paraquat was detected in the urine up to six days after exposure. A high performance liquid chromatography method for determining paraquat in tissue is described.

A case of possible malicious poisoning of dogs by endrin was investigated. A variety of tissues were analysed. The stomach contents of one dog contained 5 g/kg endrin. The results are compared with recorded data from feeding studies pursued elsewhere to aid the diagnosis of dieldrin and endrin intoxication. A number of organochlorine compounds closely related chemically to endrin were tentatively identified.

Two separate incidents of poisoning, one involving the death of 10 cattle and the other four sheep following the use of sodium monochloroacetate, were investigated. The cattle drank from a farmyard drain overflow which undissolved herbicide entered. Sheep had access to spilt herbicide by a standpipe. Sodium monochloroacetate appears to be equally toxic to both sheep and cattle. The need to follow the manufacturers' instructions is emphasised.

The cases of suspected poisoning of livestock by a range of organic chemicals, mainly pesticides, investigated at the Central Veterinary Laboratory during the period 1977 to 1980 are reviewed. The incidences of poisoning by various types of compound and the species most at risk are discussed. Organophosphorus pesticides and rodenticides were the commonest causes of poisoning. Pesticides accounted for one in 25 of all fatal poisonings listed by the veterinary investigation diagnosis analysis (VIDA) of the Ministry of Agriculture, Fisheries and Food.

Ectoparasites of sheep in Britain include the tick Ixodes ricinus, the blowfly, Lucilia sericata, the ked, Melophagus ovinus and the lice, Damalinia ovis and Linognathus ovillus. The most important ectoparasite, however, is the mite Psoroptes communis ovis which causes sheep scab. This notifiable disease was eradicated from Britain in 1952 but was reported again in 1973. The control of ectoparasites depends largely on the efficient application of insecticide to the fleece and skin. Plunge dipping in a bath is generally regarded as the most efficient method and is compulsory for the control of sheep scab but it is not always the most convenient. After the eradication of sheep scab in 1952 plunge dipping was no longer compulsory and jetting, spraying and showering techniques were then employed for the other ectoparasites.

The determination of warfarin in liver, blood, urine and feedingstuffs by high-pressure liquid chromatography (HPLC) is described. Clean-up is simple and the lower limit of determination is about 0.025 ppm. Recoveries from liver are about 85% over the range 0.025–1.0 ppm; recoveries from blood range from about 67 to 90%.

Bacterial thiaminase I associated with cerebrocortical necrosis of cattle and sheep is shown to utilise Δ1-pyrroline and related compounds as cosubstrates. The product resulting from the reaction of thiamine and Δ1-pyrroline is 1-(4-amino-2-methylpyrimidin-5-ylmethyl)-1-pyrrolinium chloride. This compound has been identified in the brains of calves suffering from cerebrocortical necrosis. The implications of these findings in the aetiology of other thiamine-responsive diseases of the central nervous system are briefly discussed.

A rapid method for the gas-chromatographic determination of diazinon and dichlorvos in blood is described. Protein is precipitated by mixing the blood with an excess of acetone containing an internal standard and the supernatant liquid is injected, directly or after concentration, into the gas chromatograph. A thermionic phosphorus detector is used.Recoveries are satisfactory from 0·1 ml of blood containing 0·1 p.p.m. of the pesticide without concentration of the extract. If a 1-ml sample is used and the extract concentrated, 0·02 p.p.m. can be determined. It is suggested that the method should be applicable to a wide range of organophosphorus pesticides.The method is also shown to be effective for determining diazinon in tissues and organs, but it is not recommended for this purpose.