Spring eczema: the search for the cause(s) continues (abstract)

Authors: Collett MG
Publication: New Zealand Veterinary Journal, Volume 54, Issue 1, pp 50, Feb 2006
Publisher: Taylor and Francis

Animal type: Cattle, Livestock, Production animal, Ruminant
Subject Terms: Biosecurity, Disease surveillance, Environment, Pathology, Photosensitivity, Toxicology, Disease/defect, Research/development, Seasonality/photoperiod, Integument/skin/wool/hair/fur/feather
Article class: Abstract

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Abstract: The cause(s) of spring eczema (SE), a photosensitivity disease that afflicts calves and adult cattle, remains elusive. Putative causes include: an inherent (calves) or acquired (e.g. previous sporidesmin-induced liver damage in adults) inability of the liver to cope with the huge amounts of chlorophyll in pasture during spring in New Zealand; immaturity of the liver in early-weaned calves; high levels of artefactual chlorophyll degradation products in manufactured calf feeds; and disturbance in ruminal microbial metabolism. A small trial was conducted where a daily dose of 2 kg of fresh, finely cut storksbill (Erodium moschatum) was administered to two aged, rumen-fistulated sheep for 9 and 4 days, respectively. Although the second sheep did develop a raised glutamate dehydrogenase activity (498 IU/L) prior to termination of the experiment, no photosensitivity was elicited.
Seven farms (Taranaki, Bay of Plenty, Manawatu) experiencing outbreaks of SE in Friesian and Hereford-cross calves were visited. The prevalence of SE in the calves varied from 8–54% (average 25%). Storksbill was present on only 2/7 properties. On all the farms, calves were eating manufactured calf pellets containing 16% protein and monensin. Tests for phylloerythrin in plasma and for fluorescent compounds, such as pheophorbide, in the feed will help to elucidate whether SE is primary or secondary and whether calf feeds are involved.

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