Fire crews from Harold Hill, Hornchurch, Romford and Dagenham fire stations attended.
Around 40 firefighters attended to the blaze at Chapmans Farm Stables, Hall Lane at around 4.30am on Sunday morning.
Two horses died at the scene. One horse was led to safety by a staff member before the arrival of the Brigade.
A large area of the stable block was destroyed, including the majority of the horses equipment.
The fire was under control by 5.46am.
Two young sisters “very much loved” both horses and considered them to be their “best friends”.
“Any funds raised will be used to help replace their horses and all of their equipment that was also lost in the fire,” said John Fogerty, who has helped organise the fundraiser.
The cause of fire has been recorded as undetermined but it may have been started by either an electrical failure or self-heating event.
Anyone wanting to donate, can do via the fundraising page.
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Tags: Upminster, London Fire Brigade