Firefighters went to the aid of a horse that was stuck in a ditch.
A fire crew from Buckingham were called to a farm in Deanshanger Road, Lillingstone Lovell, at about 1.45pm.
Firefighters also requested the specialist aniimal rescue unit from Wellingborough to attend.
A Bucks Fire & Rescue spokesman said: “We didn’t use the blue lights or sirens as we went to the incident because nothing upsets a horse more.
“They can be very worried by the noise and flashing lights.”
Crew manager Kieron Thomas said the 20-year-old mare had collapsed in a muddy ditch and was exhausted and unable to get up.
The horse had been in the ditch for about 18 hours when she was found.
Firefighters spent about an hour and a half at the scene, assisting the owner and the vet, who had sedated the horse.
Mr Thomas said: “We were planning to use a crane to lift it out of the ditch.
“But the horse’s health deteriorated and theowners took the sad but humane decision to put the horse to sleep.
“It wasn’t a happy ending but at least we could provide support to the owner and the vet.”
Mr Thomas added that owners of large animals should not hesitate to call 999 if they need the assistance of the fire service, and specialist advice is available from the Bucks Fire & Rescue control room.