with Phil Rennie
Clinical cases of facial eczema are now being seen in the Bay of Plenty. Rain has hit most parts of the North Island over the past month and with the humid weather continuing, all farmers should be monitoring spore counts closely as part of their facial czema prevention programmes.
Signs to look for include a drop in milk production in cattle; animals that are restless, seeking shade and cows that lick their udder; and exposed, unpigmented or thin skin that reddens, thickens and peels.
Not all affected animals will show signs. For one clinical case there are likely 10 animals with subclinical liver damage. These animals will have reduced production – growth or milk. Chronic wasting or death can occur from a badly damaged liver, especially under times of stress.
The fungus Pithomyces chartarum produces spores (containing the toxin sporidesmin) when grass minimum temperatures are above 12°C for two or three nights and humidity is high. This combination can last from December/January right through to May.
High spore counts
Animals need to be treated two weeks prior to the rise in spore counts to have adequate protection. Avoid hard grazing and topping pasture during these times.
With more showers expected heading into the autumn, spore counts could stay high with mild temperatures. All farms should be on high alert, monitoring spore counts closely and carrying out their own on-farm assessment of the risk.
What to do
Oral zinc oxide prevention, preferably through slow release boluses, offers best performance. In-line zinc sulphate water systems is the other main prevention alternative for stock.
There is no specific treatment for facial eczema and any therapy considered should be symptomatic and palliative. Antihistamines, anti-inflammatories, vitamins and zinc-based creams for skin lesions are commonly given.
For more information on facial eczema in your area, contact your local vet clinic for advice and treatment options.