FORT WORTH, Texas (CBSNews.com) - A Texas family is accusing a veterinarian of keeping their dog imprisoned in a cage and using it for blood transfusions for six months after they thought their pet had been euthanized due to health problems.
The dog's owner said she had given Dr. Lou Tierce of the Camp Bowie Animal Clinic in Forth Worth permission to euthanize her then 4-year-old Leonberger, Sid, last October because the veterinarian told her the dog had a degenerative health condition, CBS Dallas/Fort Worth reported.
But last week, Marian Harris heard from a former employee of the vet's clinic, who told her Sid was still alive.
"The betrayal is so incredibly intense that nothing you have prepares you for the emotions," Harris said. "There's anger, there's joy that you have your dog back, there's betrayal of this intense trust. And so it's just really hard to camp on one particular emotion."
Harris said Tierce had told her that Sid was suffering from a degenerative spinal condition. She and her husband, Jamie, agreed that the vet should euthanize the dog to spare him suffering.
But the former clinic worker told Harris that the vet kept Sid alive -- in a cage - and used him as a doggie blood donor, Harris told the Fort Worth Star-Telegram.
Harris said she and her husband marched into the Camp Bowie Animal Clinic and found Sid in a back room.
"He was able to walk and jump in the back of my minivan so it was an excitement to be reunited," Harris said.
They immediately took him to another vet for an evaluation, who told them that Sid did not have any serious health problems.
Sid is now back home in Aledo with the Harris family.
Police and the state Board of Veterinary Medical Examiners are investigating whether any other animals may have been abused at the clinic. Animal control removed two other dogs from the clinic.
Tierce, a licensed vet since 1966, called the allegations "a bunch of hooey" on Wednesday and said he had kept Sid alive because he couldn't bear to put him down.
"The lady wanted me to euthanize their dog, but I just couldn't bring myself to do it," Tierce said, according to the Star-Telegram.
He said the allegations were fabricated by a disgruntled employee who "wanted to get me."
The former clinic worker, Mary Brewer, told the Star-Telegram she quit because animals were being mistreated at the clinic.
"I knew the truth and I quit because of it," Brewer said. "I'd had enough. ... Right is right and wrong is wrong."
© 2014 CBS Interactive Inc. All Rights Reserved.