Sixteen of the 18 horses that travelled on a Spirit of Tasmania ferry trip in 2018 likely died about eight hours into the voyage, a court has heard, and the two that survived were the last loaded onto their converted refrigeration trailer.
Ferry operator TT-Line is fighting 29 charges of breaching the animal welfare act, including that it failed to ensure the horses were individually stalled and to ensure there was adequate ventilation.
The Burnie Magistrates Court has heard the professional polo ponies were exposed to high temperatures, increasing their respiratory demand, and likely died about eight hours into the voyage across the Bass Strait.
Sophie Doake, a vet based in Victoria, told the court she had not been informed of the fate of the other horses when she was called to help.
She said one of the two surviving horses had a respiratory rate of 40 breaths per minute, far above the eight to 16 that would normally be expected.
She also said that horse had a heart rate "double what it should have been".
As a result, Dr Doake said the horse would have "without a doubt" been in a level of pain.
It was only after she completed her examination of the horse she was informed of the circumstances of the incident.
She said it was her understanding that the horse was the second last to be loaded on the trailer.
The only other surviving horse was in good condition, and Dr Doake understood that horse was the closest to the trailer's tailgate.
The court had previously heard a gap where the tailgate is situated meant more air was able to get in.
More evidence to come
Evidence in the long-awaited hearing against the state-owned company began to be heard on Thursday after TT-Line's defence lawyers launched multiple unsuccessful attempts to adjourn the proceedings.
The court began hearing evidence from an investigator into the deaths, Biosecurity Tasmania's Debra Grull, who appeared in court on Friday.
Dr Grull told the court she had transported up to six horses at a time across Bass Strait in a personal capacity.
"It's about making sure that the horse not only merely survives the transport but undertakes the crossing well," she said.
Dr Grull said well-ventilated transportation was "crucial" to a horse's health and welfare.
Defence lawyers argued Dr Grull did not demonstrate any specialised knowledge in horse transportation.
They said comments around ventilation were "opinion" and she did not have adequate qualifications to make them.
Magistrate Leanne Topfer ruled Dr Grull was able to give the evidence.
The hearing was adjourned until next week, when Dr Grull will continue giving evidence.
Former Australian polo captain Andrew Williams, who was driving the trailer, changed his plea to guilty in July to charges arising from the incident.
He is due to be sentenced at a later date.
