Facial eczema spore counts are already at danger level for lambs in Turakina and Fordell - and could leap skyward after rain in these hot conditions.

There was about 10mm of rain in Turakina and Fordell on January 24, and facial eczema spore counts lifted to 30,000 there. Spore counts are a danger to lambs when they are more than 20,000.

Wanganui Veterinary Services had been doing spore counts for two weeks, general manager Tom Dinwiddie said.

Since the rain, conditions have been hot and dry, which kills the spores. But their levels could rise quickly if there is more rain, which MetService predicts for Friday.

Advertisement

If that happened, and the weather continued to be hot and still, farmers should be ready to act quickly to protect their stock, Dinwiddie said.

Facial eczema is a disease caused by the spores of fungi that feed on decaying vegetation. It affects sheep, cattle and deer.

The spores contain a toxin that stops the animals' livers functioning. The outward signs include lower production, skin irritation and peeling and animals avoiding the sun. Severely affected animals can die.

The spores are more common when weather is warm, damp and still.

The disease can be stressful and financially devastating for farmers. It was particularly bad in 2016, and even affected farmers in Taihape, who don't usually have to worry about it.

The spore counts are highest from January to May, and can spike in March and April. The final few weeks of March are often the worst.

Remembering the deaths in 2016, farmers will be taking steps to prevent facial eczema - mainly spraying fungicide on pasture, moving stock to pasture with low spore counts, selling stock early or giving the animals zinc capsules that will protect them for six weeks.

"I think every farmer should have a plan, and keep monitoring the spore levels," Dinwiddie said.