Information for Victorian Veterinarians
Equine Influenza (EI) is a notifiable disease under the Victorian legislation. Call the 24 hour Emergency Animal Disease Hotline: 1800 675 888 if you suspect EI.
Equine influenza is a highly contagious viral disease of horses. Until the 2007-08 outbreak, the disease had been exotic to Australia. Due to the efforts of the horse industry and government, EI was successfully eradicated from Australia.
Although EI has been eradicated, we will still need to maintain our vigilance and be on alert for suspect cases. Veterinarians are therefore asked to assist Department of Economic Development, Jobs, Transport and Resources (DEDJTR) in continuing surveillance. Ongoing passive surveillance, involving the investigation of any horses showing signs consistent with EI, enables Australia to demonstrate to our international trading partners that EI has been eradicated.
A co-operative approach between private veterinarians and Department of Economic Development, Jobs, Transport and Resources (DEDJTR) Victoria staff is sought for all investigations to ensure that:
- Supplies and support for sampling are provided to private veterinarians as required
- Duplicate samples are collected and submitted to the Agribio Centre, Bundoora
- Data is managed so that DEDJTR Victoria is aware of all investigations and their outcomes
- Disease is not transmitted between properties in the process of surveillance
- A professional and safe investigation is conducted.
When DEDJTR requests an investigation and/or sample collection that will be undertaken by a private vet, the Chief Veterinary Officer has authorised the payment of the disease investigation subsidy ($300 plus GST) to the veterinarian involved. This is in addition to the lab costs which are already being covered by DEDJTR.
DEDJTR staff can assist veterinarians with the submission of samples to the Agribio Centre, Bundoora. Viral transport medium can be obtained from your local Animal Health staff.
The following information relates to the investigation by veterinarians of suspect cases of EI in Victoria.
Clinical signs of EI include sudden onset of fever (38.5 to 41.0 °C), a deep, dry hacking cough and a watery nasal discharge which may later become muco-purulent. Animals may become depressed, go off their feed, have laboured breathing and muscle pain and stiffness.
The maximum incubation period is five days and horses are infective for 14 days. Most shedding of the virus occurs in the early stages of disease when coughing is most pronounced.
Transmission of the EI virus to humans under natural conditions of exposure has not occurred during outbreaks of EI in horses. The virus can survive on skin, fabrics and the surface of contaminated equipment. Contaminated horse transport vehicles, equipment, grooms, and people who have close contact with horses are all important in transmitting infection between places.
The EI virus is relatively fragile and is killed by exposure to sunlight for 30 minutes. It is also susceptible to soaps, detergents and many other disinfectants which are suitable for personal disinfection. Instruments and veterinary equipment should be washed with soap or detergent and water and disinfected with chlorhexidine, phenolic disinfectants or bleach.
Prevent Spread of Infection Between Horses and Between Premises
Care must be taken not to spread potential infection. Contaminated equipment and personnel can easily transfer the 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 and water and disinfection.
Entry onto Property
When investigating a suspect case, it is advisable not to take your vehicle onto the property. If you are examining a horse highly suspicious of EI you will need to decontaminate the vehicle prior to leaving. Wear rubber boots, gloves and overalls. A clean pair of overalls must be worn if subsequently visiting another property.
Examination of Horses
- Use a minimum of your own equipment for examining and sampling horses. You need the following: thermometer, swabs and virus transport containers, vacutainers for clotted blood samples and needles/vacutainer holder or syringes, plastic bag or cleanable container to hold all samples after collection.
- Use the owner's restraining equipment such as halters and twitches. Disinfect this between horses.
- Record the identity of each horse examined.
- Examine all suspect horses. Note body temperature and respiratory signs including coughing, dyspnoea and nasal discharge.
- Record history and clinical signs.
- If examining more than one horse in separate areas of the property, be careful not to spread viral material. Wash hands with soap and water, consider changing overalls and disinfecting boots and examination equipment between horses.
Immediately telephone the DEDJTR on 1800 675 888 or local DEDJTR animal health field staff if you suspect EI.
Samples to be Collected
For each suspect horse collect:
- Two nasal swabs. A normal 6 inch wooden or plastic handle cotton swab is satisfactory. Insert the swab deeply into both nostrils and vigorously swab the nasal septum and ventral meatus. Place the swab into virus transport media. Repeat the process for the duplicate sample (into a separate viral transport media vial). The virus does not survive well on dry swabs, and samples must be immediately placed into a viral transport medium which contains antibiotics. Appropriate media can be obtained from DEDJTR Diagnostic Veterinary Laboratory, Attwood. This media should be kept frozen until use. Once defrosted and refrigerated the shelf life is 2 weeks. Transport media such as Stuarts and Amies are NOT suitable as they do not contain anitbiotics.
- Two 10ml clotted blood samples. Do not refrigerate the blood samples until the serum has started to separate.
Advice to Owners
Advise the owner regarding isolating the horse(s) and actions to prevent disease spread such as:
- 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 owners telephone their veterinarian if horses show signs of disease or any temperature elevations
- Restrict access to the horses and keep them way from boundary fences
Dedicate a person to deal with these horses only. This person must decontaminate and disinfect before being allowed near other horses.
Exit off the Property
- Package specimens into a plastic bag and take back to car. At car, rinse the outside of the bag using soap, detergent or disinfectant and pack into 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 and place in vehicle.
- If possible disinfect any equipment you have used while still on site eg: thermometer, vacutainer holder. Otherwise double bag these and disinfect back at the clinic. Use a disinfectant such as Vikron® or chlorhexidine. If this is not available, wash thoroughly with detergent or soap.
- If EI is highly suspected, you must shower with soap and shampoo hair, blow nose, change clothes and immediately avoid contact with other horses.
- If this is a new suspect case of EI, contact the DEDJTR immediately if you have not already done so.
- Launder clothes and hats with detergent and hot water. Alternatively, keep clothing sealed in a plastic bag until negative results are received.
- Instruments and veterinary equipment should be washed with soap or detergent and water and disinfected with Virkon® , chlorhexidine, phenolic disinfectants or bleach.
Once you have visited a property which you believe has EI suspect horses, you must not visit another horse property for 24 hours.
Submission to Laboratory
- Samples should be kept chilled e.g. use ice bricks and esky. The esky should be sent to DEDJTR Agribio, 5 Ring Rd, LaTrobe University Bundoora, inside a securely taped cardboard box. The description of goods on the consignment note should be labelled "Diagnostic samples".
- Samples should arrive at the laboratory within 24hrs. Samples are still OK up to 48hrs if kept refrigerated.
- A completed laboratory submission form and Record of Disease Event (RODE) form must accompany the samples (contact your local DEDJTR Animal Health staff for these forms).
- Samples will be tested by an Influenza A PCR. This is a screening test. If this returns a positive result the second swab sample will be forwarded to AAHL for confirmatory testing.
- Record of Disease Event Form
- Equine Influenza Submission Form
Submit samples to:
Department of Economic Development, Jobs, Transport and Resources
5 Ring Road
Bundoora VIC 3086
If you require further advice or help with the collection or submission of samples contact your local Animal Health staff or the DEDJTR all hours Emergency Animal Disease hotline on 1800 675 888.
DEDJTR Customer Service Centre: 136 186
24 hour Emergency Animal Disease Hotline: 1800 675 888