The BBC's Ishbel Matheson reporting from Cheltenham Magistrates' Court

A third policeman was cleared of a similar charge.

All four officers were based at the Essex Police Dog headquarters in Sandon when the incidents took place.

One of the dogs - Acer - died after being kicked while hanging from his lead.

Sergeant Andrew White, 38, was convicted at Chelmsford Magistrates Court of seven charges under the Protection of Animals Act.

Pc Kenneth Boorman, 45, was found guilty of six charges under the same Act and Pc Stephen Hopkins, 42, was convicted of one offence.

Scene of cruelty: The Essex police dog centre

White and Boorman were given four-month prison sentences but were bailed unconditionally pending appeals against conviction and sentence.

Hopkins was ordered to do 200 hours of community service and pay £1,000 towards prosecution costs. His lawyers said they would also appeal against the conviction.

The BBC's Sally Chidzoy reports on this cruel case

The head of the training centre, Inspector Graham Curtis, 43, was found not guilty of three charges of failing to issue an order to prevent unnecessary suffering to animals.

Speaking after the trial, Mr Curtis said: "I have and would never condone any form of cruelty of any kind to any animal."

Inspector Graham Curtis: Cleared

It was alleged during the three-week trial that dogs who misbehaved were swung around in the air by their leads "helicopter fashion".

Their choke chains were used to hang them from fences and posts as they were beaten.

The death of Acer, who was raised from a puppy by police, horrified dog lovers across the world and caused untold damage to the image of all professional dog training centres.

Sergeant White had said routine physical abuse of Essex police dogs had been going on since at least the late 1970s.

Animal charities shocked

Police say that while the case is horrifying, it is an isolated incident.

But the RSCPA says that unless the police have an independent inspection regime in its dog units there are no guarantees that this kind of incident will not happen again.

In light of the evidence, the RSPCA has put a ban on its dogs being rehoused in police training centres across the country.

Jim Phillips, vet officer at the RSPCA, said: "We would like to see the establishment of national training centres where the trainers are properly trained and, more importantly, that there is a national methodology and code of practice."