News of the death of seven month- old pup Tammy went viral after it was shared by almost 1,000 people on Facebook.
Save Our Street Dogs (SOSD), from which Tammy was adopted, had posted on its Facebook wall allegations from Tammy's re-homer about the adoption.
The unnamed re-homer claimed that Ms Alison McElvee had tried to return the puppy, but had not responded after being told that she had to pay part of the cost of having to board the animal until another owner could be found.
It was also alleged that they were told the puppy was put down only after they made a police report and police were called in during a confrontation with Ms McElvee at her home.
The news enraged animal activists and netizens, who took up virtual cudgels against the owner and the vet involved in putting down the pup.
Some posted her photo online, revealing where she works and labelling her "puppy murderer", while others called for a boycott of the clinic. There was even talk of activists going to the woman's workplace to confront her and picketing outside the veterinarian's clinic.
Tammy's owner removed her Facebook account and was not at work when The New paper visited her office on Monday.
SOSD posted on its Facebook wall that while it encourages open discussion and freedom of opinion, it does not tolerate the use of racial slurs and threats.
The Society for the Prevention of Cruelty to Animals declined comment "until all the facts are known and clarified from all parties concerned".
An Agri-Food and Veterinary Authority's spokesman said it is looking into the matter and liaising with the pet clinic and the relevant parties involved.
She said the decision to euthanise a pet is made by its owner after consulting a veterinarian, who must examine the animal and assess that euthanasia is necessary.
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