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1 February 2000
Farmers should keep up their supply of zinc to combat facial eczema, or risk being caught out as they were last year, warns Ross Burnell, MAF’s Animal Welfare Senior Advisor.
Last summer and autumn there was a shortage of zinc on the market and Mr Burnell says the facial eczema risk will be high again this year as La Nina, the predisposing factor causing concerns last season, will be present again this year.
Last year facial eczema-affected sheep and cattle suffered skin lesions, illness, deaths and significant adverse effects on growth rates and fertility throughout the North Island and northern parts of the South Island. While affected stocks have recovered many cattle and sheep will have residual liver damage, which will predispose them on-going health complaints.
The Ministry of Agriculture and Forestry recently contacted zinc suppliers to ensure farmers would have access to enough licensed zinc products to see them through the upcoming facial eczema season.
It is an offence to use an unlicensed animal remedy and submit for slaughter an animal treated with an unlicensed remedy except where it has been prescribed by a Veterinarian for animals under their care. Farmers doing so face criminal prosecution and financial loss by having carcasses condemned when submitting them for slaughter.
Ross Burnell says the risk of a facial eczema outbreak could continue until April, and possible even into May.
"Early detection of facial eczema is possible with good observation," he says, "prompt treatment of affected animals not only prevents further suffering but helps to prevent weight loss, wool and skin damage and deaths."
Facial eczema is a type of photosensitisation or exaggerated sunburn which affects livestock, mainly sheep and cattle, in all but the south half of the South Island. It is caused by a toxin in fungal spores on a pasture that causes liver, then skin damage. Over a period of time, severe lesions can result in jaundice, ill thrift and death.
The first sign of facial eczema is usually reddening and swelling of skin exposed to the sun. The areas most commonly affected are around the eyes and over the nose. The skin weeps and can become infected. Shade can provide relief for affected animals as well as help prevent further damage. Affected animals often seek the shade of trees or hedges.
A good means of prevention is giving zinc by mouth, either in the form of drenches or long-acting boluses. For cattle, zinc solutions can be added to the drinking water. There are other means of prevention involving preferentially grazing safer pastures and spraying pasture with fungicide, and taking part in spore monitoring schemes can be invaluable in assessing the current level of risk.
For further information contact:
Ross Burnell, MAF Enforcement Unit Senior Adviser, phone: 09 256 6423, or fax: 09 298 6915