Investigation procedures for vets

Sample collection

Collect initial samples from:

1. Horse(s) that have died quickly and without obvious cause
2. Live horses that are on the same property as horses that have died quickly and are showing acute signs of disease

For dead horses, initially collect:

1. Nasal and rectal swabs (both in duplicate)
2. Serum in plain tube and whole blood in EDTA, (duplicate of both if possible)
3. Aqueous humour in sterile (yellow top) container

For dead horses following Hendra exclusion, a full necropsy is indicated.

• Please discuss suitability for specialist pathologist necropsy with Agriculture Victoria prior to proceeding
• For field necropsies:
  • Use of PPE is still of critical importance, including impervious boots (for example, gumboots), overalls and gloves, safety eyewear and P2 respirator mask
  • For required tissues, refer to the SIGNIFICANT DISEASE INVESTIGATION (SDI) GUIDE - HORSES.pdf (PDF - 620.3 KB)

For acutely sick horses on a property where a horse has died suddenly:

1. Serum and whole blood in EDTA (both in duplicate)
2. Nasal and rectal swabs (both in duplicate)
3. Faeces – 50ml sterile (yellow top) container
4. Urine (if possible) – 50ml sterile (yellow top) container

In addition, for all investigations, instruct the owner not to discard any relevant feed samples, and:

1. collect and hold feed:
   1. hay and hard feed/concentrates: 1-2kg in plastic bag – labelled (owner/property address/ propriety name/date collected) photograph of batch details from feed bag
   2. weeds: full plant with wet newspaper around roots in paper envelope preferrable
   3. supplements (including licks): do not discard
2. collect and hold up to 2L of water which horses may have access to

Packaging of samples

Standard packing systems for dangerous goods apply (three layers between potentially infected liquids and a person).

See: https://agriculture.vic.gov.au/biosecurity/animal-diseases/vetsource/submitting-specimens-to-the-laboratory

For blood samples and containers containing swabs, urine or manure:

Wipe the tubes so that they are free of contamination before packing. Prevent the tubes rattling around in transit with a rubber band or polystyrene tray.

• 1st layer - Blood is contained within a sealed plastic vacutainer.
• 2nd layer - Put in a sealed plastic bag. Use a cold pack, not ice, in the esky with absorbent material sufficient to absorb any liquids in the esky such as a disposable nappy.
• 3rd layer - sealed in an esky within a solid cardboard outer.

Accession form paperwork should be outside the sealed esky but inside the outer box, so it is the first thing seen on opening

Transport

Chill blood samples and unpreserved tissue samples at either 4°C, or with frozen gel packs.

Do not freeze samples unless processing and shipping is going to be delayed; freezing can reduce the sensitivity of virus isolation and molecular diagnostic tests. Send samples with dry ice if the journey is expected to take several days.

Sample submission

Agriculture Victoria officials including AgriBio (the Victorian state laboratory) staff will perform testing or coordinate sample packaging and consignment for delivery to CSIRO-ACDP, if needed. Veterinarians should contact their local district vet or the Emergency Animal Disease hotline on 1800 675 888 to arrange sample submission.

Diagnostic tests

Testing is being performed for a wide range of infection and non-infectious causes.

Notification

Upon suspicion of any notifiable or emergency animal disease in Victoria it must be immediately reported to Agriculture Victoria through direct contact with your local District Veterinary Officer or the Emergency Animal Disease Hotline on 1800 675 888.

See: https://agriculture.vic.gov.au/biosecurity/animal-diseases/notifiable-diseases

Significant Disease Investigation (SDI) Program

Investigation and testing of suitable cases is covered by the Victorian Significant Disease Investigation (SDI) Program.

Following reporting, Agriculture Victoria field staff will provide private veterinarians with direction and assistance to manage significant disease investigations, including eligibility and information requirements for SDI funding.

For more general resources, please refer to the Agriculture Victoria website.

Further information:

• 17 July 2023: Veterinary advisory
• Plants Poisonous to Horses: An Australian Field Guide