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Biomedical subjects

J B Spence

Publications and source records attributed to J B Spence.

18 recordsLinked to original sources

An investigation of bovine serum copper levels in Lincolnshire and South Humberside.

Analysis of more than 2000 bovine serum samples showed a large monthly variation in copper levels. There was also a difference in levels between beef and dairy cows although all showed the same monthly pattern. This monthly variation was correlated with rainfall; the higher the rainfall the lower the copper level. The interpretation of single herd blood copper values must be considered carefully in view of this variation.

Animals↗

Investigations of a flock heavily infected with maedi-visna virus.

Following the discovery that a flock of sheep in England was infected with the virus of maedi-virus, several seropositive sheep were brought to the Central Veterinary Laboratory and kept isolated and under observation for up to three years before being further examined at necropsy. Meanwhile, sheep in the infected flock which died or were culled were examined after death for evidence of the actual disease. At necropsy pulmonary disease was a common (although not always the sole) finding, the lesions being mostly chronic pasteurellosis and pulmonary adenomatosis. One of the 45 carcases examined showed classical lesions of advanced maedi. In four others, early or incipient lesions of maedi were found in otherwise normal lungs, while in three more, maedi was coincidental with the other pulmonary diseases. No clinical evidence to suggest maedi, other than emaciation, was seen in any of the sheep with lesions of the disease.

Animals↗

Salmonella gona infection in sheep.

A field outbreak of salmonellosis due to Salmonella agona in sheep and some subsequent experimental work is described. While the field outbreak in pregnant ewes and neonatal lambs caused severe losses the experimental disease in non-pregnant sheep was mild and transient. S agona was not isolated from the carcases of the experimental sheep killed after 28 days post infection but it persisted for 69 days in the faeces of one ewe which was kept alive for three months. Media comparisons indicated that selenite enrichment broths incubated at 43 degrees C and plated on to brilliant green agar gave the most satisfactory cultural results.

Abortion, Veterinary↗