Summary of Hendra virus incidents in horses

Hendra virus (HeV) was first isolated in 1994 in horses at a racing stable in Hendra, Brisbane.

The table below shows the location and date of each confirmed and possible HeV equine case in Queensland and New South Wales, including clinical signs, observations in horses and other relevant information.

Date	Location	Confirmed	Untested/ unresolved horses	Clinical signs and observations*	Other relevant information
July 2025	Southeast Queensland	1	0	Initially dull and febrile, then developed breathing difficulty (increased respiratory rate and effort) and died after rapid deterioration. Unvaccinated against HeV.
July 2023	Newcastle	1	0	Inappetant, febrile, ataxia, depression, bilateral serous nasal discharge, injected membranes, unvaccinated for HeV. Some initial treatment was provided, but deteriorated and died 24 hours later.
July 2022	Mackay	1	0	Off food, trouble chewing food, staggering, disoriented and swollen muzzle. Unvaccinated against HeV.
October 2021	West Wallsend near Newcastle (NSW)	1	0	Neurological signs. Unvaccinated against HeV, euthanised after rapid health deterioration.	This case was diagnosed as Hendra virus variant (HeV-g2).
June 2020	Murwillumbah (NSW)	1	0	Depressed and having difficulty breathing, euthanised after rapid health deterioration.
June 2019	Scone, Upper Hunter Valley (NSW)	1	0	Sudden onset of neurological signs and unresponsive, euthanised.
September 2018	Tweed Heads (NSW)	1	0	Depressed and not eating. Worse by the next morning, fever and staggering, euthanised.
August 2017	Lismore (NSW)	1	0	Observed unusually quiet and disoriented 1 day prior to showing clinical signs—fever, increased respiration, poor circulation, teeth grinding, euthanised after rapid health deterioration.
August 2017	Murwillumbah (NSW)	1	0	Lethargic and not eating properly, unsteady on its feet and unwilling to move, decreased gut sounds, elevated temperature and poor blood circulation function.
July 2017	Lismore (NSW)	1	0	Off feed, wobbly feet, lethargic, euthanised after health condition deteriorated.
May 2017	Gold Coast Hinterland	1	0	Depressed, inappetent, not walking, mild fever, elevated heart rate and respiratory rate, euthanised after rapid deterioration.
December 2016	Casino (NSW)	1	0	The horse had been through a period of illness. Initial clinical signs observed included: failure to graze, nasal discharge, some ataxia, mild disorientation, weight loss and oral discomfort. Further behavioural abnormalities were seen prior to death.	Initial samples collected at the start of illness tested negative for HeV PCR. Further samples collected a few weeks after the horse became unwell again tested positive for HeV serology, which showed the horse had mounted a strong immune response. Additional samples collected several days post death with 1 weak HeV PCR positive result.
September 2015	Gympie	1	0	Acute disease onset with rapid deterioration over 24 hours. Depressed (obtruded) demeanour, injected/congested gingival mucous membranes (darkened red/purple change with darker periapical line and prolonged capillary refill time), tachycardia (75 beats/min), tachypnoea (60 breaths/min), normal rectal temperature (38.0°C), muscle fasciculations, head pressing and collapse, euthanised.	This case was not diagnosed until 2021, when it was determined to have the Hendra virus variant (HeV-g2).
September 2015	Lismore (NSW)	1	0	Observed to be unwell, off food, before it collapsed.
July 2015	Atherton Tableland	1	0	Observed acutely ill 3 days before death. Ataxia, discharge, no respiratory distress.
June 2015	Murwillumbah (NSW)	1	0	Lethargy for 2–3 days before death.
July 2014	Gladstone	1	0	Altered gait, off food, depressed, mild mucoid nasal discharge, died overnight.
June 2014	Murwillumbah (NSW)	1	0	Found in a swamp, unable to stand.
June 2014	Beenleigh	1	0	Off food, small amount of green nasal discharge turned bloody at a later stage, ataxic, mild fever and toxic mucous membranes.
March 2014	Bundaberg	1	0	Off food, elevated respiratory rate, injected gums, and frothy nasal discharge after death.
July 2013	Kempsey (NSW)	1	0	Observed seriously ill and failed to respond to antibiotics.
July 2013	Kempsey (NSW)	1	0	Ataxic, elevated heart rate, mild fever; neurological signs include loss of balance, staggering and laterally recumbent.
July 2013	Macksville (NSW)	1	0	Ataxic, weak, stumbling and rolling.
July 2013	Gold Coast Hinterland	1	0	Off feed, dull, lethargic, elevated respiratory rate and mild bilateral serous nasal discharge, deteriorated to collapse, intermittent convulsions and unresponsive state, euthanised.
June 2013	Brisbane Valley	1	0	Depressed, unsteady on feet, reluctant to move, elevated heart rate and muddy mucous membranes, deteriorated and euthanised.
June 2013	Macksville (NSW)	1	0	Observed normal in the early morning and found dead in the late afternoon.
February 2013	Atherton Tablelands	1	0	Slow-moving, off food, ataxic. Found dead several days after the onset of clinical signs.
January 2013	Mackay	1	0	Slow-moving, ataxic, absent blink reflex, found dead approximately 24 hours after clinical signs were first noticed.
October 2012	Ingham	1	0	Anorexia, slight bilateral nasal discharge, laboured respiration (respiratory rate 20), heart rate 60, lowered head, unsteady on feet, progression to recumbency.
September 2012	Port Douglas	1	0	Ataxic, high-stepping (left side), death.
July 2012	Cairns	1	0	Inappetent, tremors, staggering, neurological signs worse on handling, slight nasal discharge, elevated heart rate, elevated respiratory rate, fever, delayed capillary refill time, congested conjunctival and oral mucous membranes, grinding teeth, penis protruding, muscle fasciculation, and blood from the nose at death.
July 2012	Rockhampton	3	0	Horse 1: Ataxic, apparent blindness, droopy bottom lip and salivation. Horse 2: Off food, reluctant to move, extended neck, muscle fasciculation, and increased respiratory effort. Horse 3: Off food, dull demeanour, reluctant to move, hanging head, droopy bottom lip, ataxic, mild increase in respiratory effort, and pawing at ground.
June 2012	Mackay	1	0	Horse found moribund.
May 2012	Ingham	1	0	Fever, ataxic, circling, hanging head, dull demeanour.
May 2012	Rockhampton	1	0	Elevated respiratory rate, fever, bilateral frothy nasal discharge, muffled heart sounds, and bilateral epistaxis at death.
January 2012	Townsville	1	0	Bilateral serous nasal discharge, blind, ataxic, sudden, brief irritation, dull, fever, elevated heart rate, elevated respiratory rate, oral mucous membranes injected, capillary refill time greater than 4 seconds, clotting time 2 minutes, ileus, facial swelling.
October 2011	Beachmere	2	1	Horse 1: Unknown. Horse 2: Ataxic, large distended bladder, decreased gut sounds, lethargic. Horse 3: No clinical signs observed.	A horse became acutely ill and was euthanised approximately 1 week before the first confirmed case. There were no samples available from this horse to be tested.
August 2011	North Ballina (NSW)	1	0	Depressed, ataxic, wide-based stance. Found dead approximately 12 hours after the onset of the first signs.
August 2011	Gold Coast Hinterland	1	0	Gait problem, lethargic, and fever.
August 2011	Mullumbimby (NSW)	1	0	Found dead. Observed normal by owners 15 hours previously.
August 2011	South Ballina (NSW)	2	0	Both horses (mare and foal) were found dead. Absentee owner.
August 2011	Ballina (NSW)	1	0	Slightly ataxic then recumbent 12 hours later, muscle twitching, unable to stand and euthanased 3 hours later.
July 2011	Mullumbimby (NSW)	1	0	Found dead. Observed normal by owners 18 hours previously.
July 2011	Chinchilla	1	0	Terminal nasal discharge, ataxic, recumbent, dull demeanour, respiratory signs.
July 2011	Boondall	1	0	Mild clear nasal discharge, acute onset ataxia, intermittent inappetence, lethargic fever.
July 2011	Hervey Bay	1	0	Attempting to stand but stumbling, dry faeces, fever, elevated heart rate, oral mucous membranes injected, capillary refill time less than 4 seconds.
July 2011	Lismore (NSW)	1	0	Found dead. Observed normal by owners 24 hours previously.
July 2011	Kuranda	1	0	Ataxic, disoriented, neck muscle fasciculation, circling, inappetent, recumbent, depressed.
July 2011	Macksville (NSW)	1	0	Sudden onset depression, blindness, head pressing, died 36 hours after first signs.
July 2011	Park Ridge	1	0	Incoordination, fever, very weak, progression to death overnight.
June 2011	Wollongbar (NSW)	2	0	Horse 1: Fever, congested mucous membranes, ataxic with wide-based stance, asymmetrical facial paralysis, blindness, euthanised.
				Horse 2: Depressed, fever, slightly ataxic, dyspnoea, copious amounts of nasal foam bilaterally after euthanasia.
June 2011	Logan	1	0	Ataxic, mild colic signs, fever, elevated heart rate, and bloody ocular discharge.
June 2011	Boonah	3	0	Horse 1: Colic, recumbent, thrashing. Horse 2: Twitching of muscles and eyes. Horse 3: Slight nasal discharge, dull, depressed, fever, elevated heart rate.	Test results confirmed the presence of antibodies to HeV in a dog on this property. It was reported that the dog did not show any clinical signs of illness. No HeV genetic material was detected in PCR tests of samples collected from the dog on 3 occasions over a 3-week period. This was the first reported case of HeV antibody detection in a dog outside of an experimental setting.
June 2011	Beaudesert	1	0	Increased respiratory effort, hind limb incoordination, depressed, fever, congested oral mucous membranes with petechial haemorrhage, and died.
May 2010	Tewantin	1	0	Twitching of mouth muscles, blindness, ataxia, seizures, inappetence, lethargy.
September 2009	Bowen	2	0	Horse 1: Shallow respiration, diaphragm twitching, muscle twitching, short stepping, reluctant to move, elevated heart rate, teeth grinding, head down, congested oral mucous membranes.	A companion horse euthanised a month prior to the original confirmed case was also confirmed positive through laboratory testing.
				Horse 2: Foam from mouth and nose, laterally recumbent with extensor rigidity, no gut sounds, fever, elevated heart rate, oral mucous membranes dry and congested, weak, jaw chomping, teeth grinding, rapid deterioration.
July 2009	Cawarral	3	1	Horse 1: Unknown. Horse 2: Heavy breathing, nasal froth, fever, elevated heart rate, elevated respiratory rate, blood slow to clot, difficulty walking, collapsed, died. Horse 3: Progressive neuromuscular spasms, incoordination, died. Horse 4: Possible mild neurological signs—weaving, head pressing, ataxic on day of euthanasia.	Strong epidemiological evidence exists for a horse that died 12 days prior to the first confirmed case. A veterinarian was confirmed positive for HeV infection after performing a respiratory endoscopy on the horse. A second horse was confirmed as HeV positive on stored blood samples.
July 2008	Proserpine	3	1	Horse 1: Unknown. Horse 2: Some respiratory. manifestation, head down, non-responsive, elevated heart rate, swollen muzzle, recumbent, red fluids from mouth, died. Horse 3: Short neurological illness, ataxic, recumbent, horse appeared very stressed, had trouble standing and walking. Horse 4: High-stepping, dull.	One horse has an unresolved HeV status from this incident—a companion horse was found dead several days prior to the first confirmed case. Limited clinical history consistent with HeV infection was available. A necropsy was not performed. One of the 3 horses with a positive laboratory test was non-fatally infected and antibody-positive.
June 2008	Redlands	5	3	Horses 1–3: Unknown. Horse 4: Inappetent, depressed, maniacal/erratic behaviour. Horse 5: Head tilt, ataxic, circling, inappetent, depressed, fever, recumbent periods. Horse 6: Central neurological signs, severely ataxic, inappetent, depressed, recumbent, thrashing violently. Horse 7: Depressed, deteriorated rapidly. Horse 8: Febrile, depressed.	Three horses have unresolved HeV status from this incident - all died at the veterinary clinic in the month before the first confirmed case with clinical signs consistent with possible HeV cases. Necropsies were not completed on the horses, and only limited substandard laboratory samples were available for further testing, with negative results for HeV.
July 2007	Cairns	1	0	Nasal discharge, wet lung sounds, fever, elevated heart rate, elevated respiratory rate, and terminal neurological signs.
June 2007	Peachester	1	0	Wide-based stance, rocking, relaxed penis, colic signs, inappetent, lethargic, depressed demeanour, elevated heart rate, recumbent and unable to rise.
October 2006	Murwillumbah (NSW)	1	0	Lethargic, ataxic, penile erection, disorientation, mandibular swelling, dyspnoea, fever, wide-based stance, high-stepping gait, occasional tongue protrusion, and coughing.
June 2006	Peachester	1	0	Opisthotonus, restlessness, vocalising (terminal), elevated heart rate, elevated respiratory rate, fever, markedly swollen lips, purple gums, died suddenly.
December 2004	Townsville	1	0	Depressed, fever, elevated heart rate and respiratory rate, and brownish nasal discharge.
October 2004	Cairns	0	1	Restlessness, elevated heart rate, increased respiratory effort and profuse sweating, fever, and blood-stained frothy secretions issuing from its nose.	Strong epidemiological evidence exists for this horse. A veterinarian was confirmed serologically positive for HeV after performing a necropsy on a horse that died suddenly with signs consistent with HeV. No samples from the horse were available for testing. The horse was the only identified potential source.
January 1999	Cairns	1	0	Clinical signs to be confirmed*
September 1994	Hendra, Brisbane	7	13	Clinical signs to be confirmed*	HeV was first identified and characterised as a result of this event. No diagnostic tests were available until after the event, and not all horses were tested, as samples were not retained from all horses. Strong epidemiological evidence exists for all horses involved to be considered as cases.
August 1994	Mackay	2	0	Clinical signs to be confirmed*	These cases didn't become apparent until late 1995 when HeV infection was confirmed in a person from Mackay. Testing of stored samples from horses was undertaken in late 1995.
Total		90, all deceased	20, all deceased

*The clinical signs listed are taken from laboratory testing submission forms or media releases. Not all information for all cases was readily accessible to Biosecurity Queensland.