Equine Influenza Information for Veterinarians
An outbreak of Equine Influenza (EI) occurred in Australia in 2007. The national response was successful in containing the disease to areas of Queensland and New South Wales. The last reported case occurred on 25 December 2007. On 28 February 2008 NSW was declared free of EI. Queensland announced its freedom on 14 March. Australia was declared officially free of the disease on 30 June 2008.
Surveillance will continue. If no further cases are detected it is expected that Australia will meet the OIE criteria for freedom from EI in late December 2008.
The response to the outbreak was undertaken in accordance with the AUSVETPLAN for EI PDF [1.2mb]. This manual provides comprehensive information about the disease and response procedures.
Veterinary staff must continue to practice strict biosecurity procedures when visiting horses and properties holding them.
Register your expertise for future responses
DAFF, the NSW DPI and QLD DPI&F would like to thank everyone who assisted with the response to equine influenza. Hundreds of people from all over Australia, as well from overseas offered their skills and time to fight this disease.
Should you like to register your expertise and assist with any future emergency animal disease outbreaks, please send us an email with a short summary of your skills and your contact details.
Clinical Signs of Equine Influenza
EI is a highly contagious viral disease which causes rapidly spreading outbreaks of respiratory infection in horses, donkeys, mules and asses. The disease is primarily diagnosed by:
- sudden onset of fever between 38.5 - 41ºC
[Note: in the current outbreak the fever is generally of the low to moderate temperature range] - a deep, dry, hacking cough
- a watery nasal discharge, which may become thick and contain mucus or pus.
Other signs include depression, loss of appetite, laboured breathing, and muscle pain and stiffness. Imported horses and previously vaccinated may experience sub-clinical infection.
Disease Transmission and Spread
The virus can be spread by:
- contact between infected and susceptible horses
- contact with contaminated tack or equipment
- susceptible horses coming in contact with premises or vehicles recently occupied by infected horses, which have not been decontaminated
- contact between persons with contaminated clothing and healthy horses.
The incubation period is approximately 5 days. Virus excretion may continue for 10 days. Most viral shedding occurs in the early stages of disease when coughing is most pronounced.
Previously healthy adult horses typically recover within 10 days, though coughing may persist for longer. Young foals and older horses can develop pneumonia and experience serious complications including potential fatal secondary bacterial pneumonia.
At least 30 days complete rest is recommended after infection with a longer period required if the fever lasts more than 4 days. The rest period reduces the chances of pulmonary infection.
Examination of Horses
Use minimal equipment for examining and sampling horses in order to reduce the chance of fomite transmission. You will require:
- disposable overalls
- thermometer
- swabs and virus transport containers
- vacutainers for clotted blood samples and needles/vacutainer holder or syringes, and
- plastic bags or cleanable container to hold all samples after collection
- water, soap/disinfectant, buckets and brushes.
Use the owners´ restraining equipment such as halters and twitches which should be disinfected between horses. Practice appropriate infection control between individual examinations.
Record History and Clinical Signs
Examine all suspect horses and record the identity of each horse examined (eg. microchip, freeze brand or description of markings, whorls etc).
Particularly note the temperature and respiratory signs including coughing, dyspnoea and nasal discharge. Complete the ANEMIS documentation for the property.
New South Wales
ANEMIS for horses - Inspecton Form 1 
Word [33kb]
ANEMIS for horses - Inspecton Form 2/3 Word [33kb]
Queensland
Information Package for Veterinarians (includes ANEMIS forms) 
PDF [716kb]
Samples to be Collected
For each suspect horse collect:
- 2 x nasal swabs. Use one swab for each nostril. A normal 6 inch wooden or plastic handle cotton swab is satisfactory.
- 2 x 10ml clotted blood samples. Do not refrigerate the blood samples until the serum has started to separate.
The best time to collect samples is in the initial 24-48 hours of fever, when viral titres are highest. Refer to the specific State Government guidelines for detailed information on sample collection requirements - see below.
New South Wales
Submitting samples and forms PDF [64kb]
Queensland
Information Package for Veterinarians PDF [716kb]
Submission of Samples for Testing
All samples should be sent to the designated State laboratory for EI samples.
Samples must be double bagged in a water tight inner package eg zip-lock bag, and a rigid outer package of adequate strength to protect contents during transport. The external surface of the inner bag should be disinfected before placement in the outer bag. Samples should be kept chilled using ice bricks and an esky if possible. A fully completed specimen advice sheet must be sent with the samples.
The receiving laboratory can provide further information on sample transport requirements and arrangements.
New South Wales
Queensland
Biosecurity Sciences Laboratory (BSL)
Animal Research Institute
665 Fairfield Road
Yeerongpilly, Brisbane QLD 4105
Phone: (07) 3362 9471 (Specimen enquires)
Fax: (07) 3362 9440
Infection Control and Decontamination
Contaminated equipment and personnel can easily transfer virus between horses and between premises. Influenza virus can survive on skin, fabrics and the surface of contaminated equipment.
Virus survival times can be as follows:
- Hard, non-porous surfaces, plastic, stainless steel: 24-48 hours
- Cloth and paper: 8-12 hours
- Dirty water: up to 18 days
The virus is killed by thorough cleaning with soap or detergent or appropriate use of chemical disinfectants such as chlorhexidine, bleach or Virkon®.
Care must be taken not to spread infection between horses and between premises.
Before the visit:
- Contact the property owner to determine the level of risk associated with your visit and inspection time.
- Confirm there are equids on the property or in surrounding areas.
- Arrange to shower and change at the end of the visit and bring appropriate disinfection chemicals and equipment.
- Ensure that you take ANEMIS forms with you which are available from your State DPI website.
Entry onto property
If possible do not take your vehicle onto the property. If you do so you will have to decontaminate the vehicle when you leave. Wear rubber boots, gloves and disposable overalls.
A clean pair of overalls must be worn for each property, take multiple pairs of disposable overalls as you may need to change between examinations of individual horses.
Exit from the property
Package specimens into a plastic bag, rinse the outside of the bag using soap, detergent or disinfectant, pack into outer bag and place in an esky with ice bricks. Remove overalls, gloves and hat for later disposal/washing – these should be double bagged. Wash rubber boots using soap, detergent or disinfectant provided by yourself or the property owner.
If possible disinfect any equipment you have used while still on site, e.g. thermometer, vacutainer holder. Use a disinfectant such as Virkon® or chlorhexidine. If this is not available wash thoroughly with detergent or soap.
Do not have contact with the interior of your vehicle until you complete the decontamination process.
If the examination leads you to suspect EI
If EI is suspected, you must shower with soap and shampoo hair, blow nose, change clothes and immediately avoid contact with other horses.
Instruments and veterinary equipment should be washed with soap or detergent and water and disinfected with Virkon®, chlorhexidine or bleach.
Launder double-bagged clothes and hat with detergent and hot water. Wash hands afterwards.
If this is a new suspect case of EI, contact your State Disease Control Headquarters (SDCHQ) immediately.
Once you have visited a property which you believe has EI suspect horses, you must not visit another horse property for 24 hours.
Advice to Provide Owners
Actions to prevent disease spread:
- isolate suspect horses
- feed and attend to suspect horses last and do not share equipment or tack between horses
- check the temperature of suspect horses twice daily and record
- request that the owners call if any horses show signs of disease or any temperature elevations
- restrict access to their horses and keep them away from boundary fences
- do not move their horses unless absolutely necessary. Check if a permit is required first.
- ensure transport is cleaned and disinfected before and after movement.
If you have further questions you should contact your State Department of Primary Industries.
State & Territory DPI info for Vets
The following are links to vet information on State and Territory websites - where available. (You may need to scroll down on the page you arrive on).
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