Kooralbyn Horse Deaths Update

 

After three weeks of comprehensive laboratory testing, Biosecurity Queensland believes that either scrub tick infestation or botulism was the likely cause of the deaths of 22 horses at a Kooralbyn property.

Chief Biosecurity Officer Jim Thompson said both conditions caused progressive muscular paralysis, as was seen with these horses, and it was often hard to differentiate between the two.

"Botulism is a bacteria that lives in soil and produces a toxin that affects the nervous system if ingested," he said. 

"The other likely scenario is scrub tick poisoning. Witnesses have reported that the horses first noticed to be in distress on Thursday 6 October had been carrying large numbers of ticks.

"Fatal infestations of scrub tick on adult horses have been recorded in the past.

"This has been an unusual and complex case. Biosecurity Queensland worked closely with the attending private veterinarian and Queensland Health to test a range of samples from the horses and the paddock where they were kept.

"Despite carrying out such a thorough investigation, we know from experience that test results don't always pinpoint an exact cause of death.

"However based on the circumstances, Biosecurity Queensland believes scrub ticks or botulism were most likely responsible in this case."

Test results have excluded:

• Hendra virus
• pesticides
• heavy metals (arsenic, lead, cyanide, nitrate)
• toxic plants
• water contamination
• deliberate poisoning.

Quick Link

• Visit the Biosecurity Qld website.