Facial Eczema (FE). Farmer Information Notes. Introduction

FACIAL ECZEMA NOTES

By Dr Clive Dalton

Original 1991 information written by Dr Barry Smith and Dr Neale Towers, Ruakura Agricultural Research Station, Hamilton, New Zealand.

BACKGROUND TO BLOG ON FE (2009)

In 1991 MAF’s Information Services Division produced technical leaflets called AgLinks, and I was a contributor to those as well as a technical editor getting other qualified people to write them. There were four on Facial Eczema, but they were rather heavy going I thought, and saw the need for more basic material as one-pagers in big print, so farmers need only use the relevant bits. The idea was timely, as the whole AgLink database died around 1980 when MAF's new 'commercial' managers decided we had to charge for information.

FE didn’t die with the AgLinks, so I got the two Ruakura top scientists, Dr Barry Smith and Dr Neale Towers, to write these “FE Notes” which I edited, and we mailed them out to farm advisers, telling them to photocopy the appropriate bits and give them away. We also mailed them direct to farmers on request at no charge, and told farmers and advisers to contact Barry or Neale directly for expert advice.

Smith and Towers had spent their careers on FE research at Ruakura as members of the thriving "Mycotoxic Diseases Research Group". It was closed down by the SOE AgResearch, that took over agricultural research in New Zealand.

These FE Notes disappeared along with MAF's variours divisons, but by a stroke of good luck, Neale Towers still had a copy which I have put on this Blog.

Warning: Some things have changed since 1991 so you'll have to take account of these as I have not updated the words. The only thing I have changed is to replace "contact MAF" with "contact your veterinarian'". The chemicals and products mentioned may now be out of date, so check with your veterinarian what is current. Prices are clearly out of date. Approval of products is now under the Animal Medicines and Veterinary Medicines (ACVM) Act and must also be approved by New Zealand Food Safety. Ask your veterinarian for the latest information on approved products. It is against the law to use an animal remedy that does not have a license or an approval of some sort, and your vet will tell you what happens when you use drugs 'off label'.

In 1991 we didn't remind farmers that horses don't get FE and this question comes up from time to time. Also at that time Camelids (Llamas and Alpacas) were not common on farms and we now know that they can get FE, so check with your veterinarian about prevention measures for them and treatment of sick animals. Zinc boluses for sheep and beef cattle were not invented in 1991 and counting spores in faeces instead of pasture is a recent development.

The titles of the series is as follows.
1. Facial Eczema: Cause and symptoms.
2. Facial Eczema: Fungicides in FE control.
3. Facial Eczema: (Dairy Cattle). Management.
4. Facial Eczema: Zinc oxide. General dosing information.
5. Facial Eczema: (Dairy Cattle). Zinc oxide. Long-term dosing.
6. Facial Eczema: (Dairy Cattle). Zinc oxide. Crisis dosing.
7. Facial Eczema: (Dairy Cattle). Zinc oxide. Dosing with motor-driven systems.
8. Facial Eczema: Zinc oxide. Prevention by pasture spraying.
9. Facial Eczema: (Sheep): Zinc oxide. Long-term dosing.
10. Facial Eczema: (Dairy cattle). Zinc sulphate. In drinking water.
11. Facial Eczema: (Dairy cattle). Zinc sulphate. Using in-line dispenser.
12. Facial Eczema: (Dairy cattle). Zinc sulphate. Direct addition to supply tank.
13. Facial Eczema: (Dairy cattle). Zinc sulphate. Direct addition to trough.
14.Facial Eczema: (Dairy cattle). Zinc sulphate. Using in-trough dispensers.
15. Facial Eczema: (Sheep & beef cattle). Grazing management.
16. Facial Eczema: (Goats). Management.
17. Facial Eczema: (Deer). Management.
18. Facial Eczema: (Sheep). Mangement. Minimising losses after outbreaks.
19. Facial Eczema: (Sheep). Breeding. Buying FE resistant rams.
20. Facial Eczema: (Sheep). Breeding. Breeding resistant rams.

How to find each of the above items
Copy and paste the title from the list above - and enter it into the Google search box at the top left hand side of the blog front page.

Spring Eczema
This is a condition which veterinarians say is not Facial Eczema as it occurs in spring, when FE is an autumn disease. The cause of Spring Eczema is not know, but speculation is that 'it's something in the feed".  It certainly looks like classical FE and it pays to treat it as such.

 

Picture of animal with a healed eczema scab on white area of its back

Disclaimer

This material is provided in good faith for information purposes only, and the author does not accept any liability to any person for actions taken as a result of the information or advice (or the use of such information or advice) provided in these pages.

Facial Eczema (FE). Farmer Information. Part 2. Fungicides in FE control.

Agriculture, Farming, animal husbandry, animal health, animal diseases, Facial Eczema, spraying, prevention, fungicides.

By Dr Clive Dalton

Original 1991 information written by Dr Barry Smith and Dr Neale Towers, Ruakura Agricultural Research Station, Hamilton, New Zealand.

Through the microscope, spores of Pithomyces chartarum look like brown hand grenades among the other debris on the slide.

Part 2. Fungicides in FE control.


Background

• Spraying with fungicides in late January or early February reduces the growth of the FE fungus in the pasture base and lowers the numbers of spores formed when weather conditions are dangerous.
• Pastures sprayed early remain safe for 4-6 weeks.
• Fungicides reduce the number of toxic spores produced during a danger period by 55-65 percent. They do not completely eliminate spore production.
• To achieve best control, apply fungicides before spore numbers rise.
• Except in years when conditions are extremely dangerous properly applied fungicides should prevent FE. Under extremely dangerous conditions fungicides will give partial protection markedly reducing the severity and costs of the outbreak.
  

Spraying Strategy
Farmers can spray all or only part of their farms. Individual management options, likelihood of severe outbreaks, economics and the terrain will decide strategy.

1. Spraying total grazing area

• Requires suitable farm contour for ground or aerial application to total area. This method is used on dairy or deer farms where stock managers want unrestricted access to all available grazing on their property.
• This is a relatively high cost but very effective option suited to high producing areas or to protect high value animals.
• Monitor pastures occasionally to check whether they are still safe.
• Respray after 5-6 weeks until all danger of FE has passed.
  

2. Spraying part of grazing area

• Part of the farm (perhaps one third) is sprayed to provide an area of safe pasture for grazing during dangerous conditions.
• When spore counts are high, or danger warnings are issued, stock are moved onto the sprayed pasture.
• It may then be necessary to spray a further area to provide safe pasture for the animals after the finish of the original sprayed pasture.
• This method minimises the initial cost of spraying but requires ongoing monitoring of the pastures the animals are to graze to ensure that it is safe.
• Decisions to spray additional pasture should be made early to ensure the spray is applied before dangerously high spore counts are established.
  

Fungicide sprays currently recommended for controlling FE spores are:

• Benomyl (Benlate)
• Thiophanate methyl (Topsin M4A).
  

DO NOT use orchard type fungicides such as Mancozebs (e.g. Dithane M45). They are excellent on fruit and vegetables but totally ineffective for controlling pasture (FE causing) fungus.

Spraying Techniques

• Complete spray cover is essential. Include stock races, fence lines and under hedges and shelter belts.
• Use clean water and clean equipment.
• Boom spray only. Rosette type applicators are not sufficiently accurate.
• Spray at the rate of 220 litres water/hectare. Avoid fluctuations of vehicle speed.
• Fungicide application rates and costs:

• Spray in settled weather. Rain in excess of 25 mm in a 24 hour period within 3 days of spraying will reduce the efficacy of the fungicide and make respraying necessary.
• Respray pasture after this time, or respray if additional safe pasture is required.
• Allow 5 days for mid-season spraying for pastures to become safe; only graze earlier in emergency.
• Do not spray pasture with spore counts over 200,000. The fungicide will be ineffective and the pasture will remain dangerous to stock.

Disclaimer

This material is provided in good faith for information purposes only, and the author does not accept any liability to any person for actions taken as a result of the information or advice (or the use of such information or advice) provided in these pages.