Vets recommend starting to treat for eczema
Veterinarians are warning Waikato farmers to begin preventative treatments for facial eczema after the recent spell of wet, humid weather.
These conditions have produced ideal growing conditions for the fungus Pithomyces chartarum that caused this condition among livestock.
This fungus produces spores that when eaten by livestock, cause liver damage, photo-sensitisation and often horrific skin lesions.
It accumulates in dead dry matter and the recent weather was an ideal breeding ground.
Cambridge Vets farm veterinarian Peter Briston said they had seen eczema cases already.
"We have seen some in calves recently and with this light rain drizzling over us at the moment, it's the ideal environment for the spore count to rise.
"We're certainly seeing some, the risk is increasing and I'm expecting to see more. I would recommend to farmers that they start their zinc programmes as soon as possible."
Zinc supplements were used predominantly by farmers as a preventative for facial eczema.
Briston said spore counts usually started to rise in late January and early February and this year it looked to be a few weeks earlier than usual. The good growing conditions also increased the likelihood of rank grass developing, which increased the risk of eczema.
"If you have had a lot of grass growth but then it goes rank and dead, then there is an increased risk of eczema."
AsureQuality's first facial eczema spore count of the year was released last week.
The samples, taken on January 16, showed high levels in the Waipa area at 115,000 spores per gram, 25,000 spores per gram in the Matamata region and a low count of 5000 spores per gram in Piako.
Another count by Anexa Animal Health from grass taken on January 17 showed 15,000 spores per gram in the Walton district of Matamata. The count showed 15,000 spores per gram at their Te Akau Coast Rd site in Raglan.
Anexa vet Katie Denholm said while spore counts remain low for now, it is best to start protectively dosing stock with zinc.
By the time 5 per cent of a herd had skin damage, up to 70 per cent of the herd would be liver-damaged and were at real risk of developing skin signs.
It took at least two consecutive days of moderate risk for there to be ideal conditions for spores to grow, so while each paddock on each farm can have drastic differences, it's clear that conditions at present are ripe for spore grow and farmers should be vigilant and proactive from now on, she said.
VetEnt veterinarian Emma Cuttance urged farmers to be proactive in preventing facial eczema on their paddocks and act now rather than guessing spore numbers.
"They are often putting in their management systems in February when they should have started in January."
Spore counts were often extremely variable between different areas on a farm, she said.
"At this point it doesn't seem like it's an unusual year. It seems pretty typical with how the [spore] counts are rising."
Recent "ridiculously humid" weather meant conditions could not be more perfect for spore counts to rise.
"The conditions are right and spore counts could shoot off," she said.
Cuttance urged farmers to take at least four grass samples regularly from their farms to their vets to be analysed.
Federated Farmers Waikato dairy industry group chairman Chris Lewis had begun supplementing his livestock treatments via a dosatron following the spike in humid weather.
Spore counting would have begun around the region and he urged farmers to be proactive in treating the condition.
"After this year there will probably be a lot of dead grass around and will be a perfect year for it."