The British Horseracing Authority (BHA) has published Celebre D’Allen’s post-mortem after the gelding passed away. The 13-year-old collapsed after the final fence of the Grand National, with jockey Micheal Nolan being suspended as a result of his ride.

Celebre D’Allen was treated by the veterinary team at Aintree and appeared to have made a quick recovery before travelling back to the Philip Hobbs and Johnson White. However, his condition ‘deteriorated significantly’ and his passing was announced on Monday.

Rossdales Veterinary Surgeons have now carried out a post-mortem of Celebre D’Allen, and the trainers and owners have allowed the BHA to share the findings. The examination found that the ‘exercise-associated episode’ that the gelding had experienced after the Grand National had concluded by the time of his death.

The statement continued: “However, a severe bacterial respiratory infection (pleuropneumonia) had occurred post-race which led to the horse’s deterioration on Monday evening, with the subsequent onset of sepsis or endotoxaemia (the release of harmful substances into the bloodstream from bacteria) likely to have been a key factor in the cause of death.

“Blood tests taken from the day of the race indicate that the infection had not been present in the horse on raceday, and was therefore developed after the race.

“Further bloods taken on the Monday indicated a severely compromised immune system. These indications had not been present in the bloods taken on the day of the race. This indicates that this issue emerged subsequent to the race and the exercise-associated episode.” The heart pathology did not find any issues which are believed to have played a role in Celebre D’Allen’s passing.

The report from the BHA went on to reinstate that, like any fatality, the incident would be reviewed in detail. The Grand National is examined every year by the BHA and Jockey Club as well, with the potential for changes to protect the welfare of horses assessed.

Broadway Boy was also treated by the veterinary team at Aintree after he took a heavy fall at the 13th fence. He remained at Aintree on the night of the Grand National and has since made a full recovery and returned to the Nigel Twiston-Davies yard. Jockey Tom Bellamy broke his wrist as a result of the fall.