TODAY the Daily Echo can reveal the tragic last few weeks of a dog dumped in the bottom of a Hampshire river with a dumb-bell weight tied around her neck.

The cocker spaniel had been suffering from severe ill health which may have gone untreated for years.

The plight of the dog touched the hearts of animal lovers since its cruel death was revealed by the Daily Echo.

A £9,000 reward has been donated for any information that leads to the prosecution of those who dumped it.

The spaniel suffered a heart condition, had a tumour in her mammary glands and a bad ear in the weeks before she was callously discarded in the River Test at Nursling.

Animal experts also believe she could have been cruelly treated in her lifetime and that the owners may not have sought medical treatment for any of the conditions she was suffering from.

The disturbing details were revealed as a post-mortem to determine just how the pet died proved inconclusive.

It's taken more than a month for the tests to be carried out to ascertain the cause of death, since the dog was recovered from the water on September 28.

A vet recruited by the RSPCA said she couldn't be 100 per cent sure what led to the death but remains convinced that the dog was dead before it was put into the water.

But the study did reveal that the dog, aged seven to nine years old, had suffered seriously ill health in its final days.

Now there is speculation over what led her being dumped in the water.

Vet Kimberley Evans, of Pet Doctors in Chandler's Ford, agreed the most likely explanation was that the owners wanted to dispose of a dog that was already dead without paying for a cremation.

But she would not rule out other theories, including that the dog could have suffered a heart attack from fear in the moments directly before being thrown in the River Test.

She said: "If it's a severe heart condition and the dog gets stressed enough it can die from a cardiac arrest. If you're dangling over a river with weights attached to you, it's a bit speculative but it's possible that process could have brought on a heart attack."

RSCPA vet David McDowell said: "It could well be a scenario where someone had been told their dog was ill but they let treatment lapse.

"Then this would mean she died of natural causes, and they dumped her in a river because they couldn't afford to dispose of her or because they were too embarrassed.

"It does rather strike me that it probably didn't have a happy end with a mammary tumour, a bad ear and a bad heart."

But pet detective June Bailey, from Worthing, Surrey, said: "It sounds to me like whoever owned this little dog didn't do anything for it all."

Richard Hatton, a vet at Harrier Veterinary Surgery in Hamble, said: "Anyone who would attach a weight to a dog whether alive or dead is unlikely to have much time for nursing a dog in poor health. It makes one very worried it died a cruel death but it can only be speculation."

Animal lovers all over the country have been sickened by the chilling picture of the pup being dragged out of the water with a 10-kilogram weight hanging from its collar.

Readers phoned up in their scores to pledge money for a reward fund - currently standing at nearly £9,000 - to be paid to anyone who supplied information leading to the conviction of whoever dumped the dog.

The money will now be paid, if it is proved that a crime has been committed, to whoever points the finger at those responsible.

RSPCA spokesman Lucy Harding said: "The cause of death is inconclusive. The dog was suffering from several medical conditions.

"The vet does believe that there may have been some suffering prior to death but the dog may well have died of natural causes. There was no visible trauma or bruising."