Firefighters were called out to rescue a cow from a swimming pool.
The animal was one of 25 heifers which escaped from a field at the University of Bristol's vet school in Langford on Wednesday.
The cow went into a local garden where it fell into the owner's swimming pool, damaging the cover and lining.
A farmer put bales of straw in the pool to use as steps, firefighters threw a rope around the cow and it walked out of the pool.
A university spokeswoman said the cow was "extremely traumatised" by the incident and was kept warm and treated with painkillers overnight.
Gate left open
"The effects of the swimming pool chemicals on the animal are still being established," she said.
The pool had been covered and closed for the winter but not drained.
The spokeswoman said the cows escaped through a pedestrian gate which had been left open despite having a latch and chain.
Peter Read, from the vet school, said: "We were very disappointed that someone failed to properly secure the gate, allowing the cows to escape, but would like to praise the fantastic response of the fire brigade, the farm manager, the vet and the veterinary students who dealt with this highly unusual situation.
"We are very concerned about the animal's welfare following the trauma and will continue to treat and monitor her."
Ten of the cows ended up in Redshard Lane and from there they went on to Congresbury Road, where it is understood drivers and passers-by attempted to herd them.
Mr Read said: "We deeply regret any damage to property and would like to thank the people of Langford and Congresbury for their assistance and understanding during the incident."
Three fire crews were called to the scene just after 1700 GMT.