UPDATE:

Camp Bowie Animal Cinlic veterinarian, Dr. Lou Tierce, was arrested for animal cruelty after turning himself into Fort Worth police Wednesday night. He is now out on bond.

A popular Fort Worth veterinary clinic is under investigation after a family says instead of euthanizing their sick pet the vet secretly kept the dog alive for blood transfusions.

Fort Worth police, the city of Fort Worth and state investigators are involved in the investigation that started when a client of the Camp Bowie Animal Clinic found out his beloved pet, believed to have been euthanized, was alive.

Jamie and Marian Harris said they took their dog, a 5-year-old Leonberger named Sid, to the vet to be treated for a minor anal gland issue.

After undergoing treatment, the family claims Sid had trouble walking and the veterinarian told them he had a bad spine condition that would only worsen. Court documents said the family was told the best option was to put him to sleep.

The couple and their son said their goodbyes and said they allowed the clinic to bury Sid on the vet's farm.

Six months later, the Harrises said they received a call from a veterinarian technician, Mary Brewer, who told them Sid was alive and being used for blood transfusions while being kept in a cage most of the day, surrounded by his urine and feces.

"I told her, 'He's still here,' and she's like, 'Can he walk?' and I said, 'Yeah, he's here waiting on you. If you came today, he'd walk out and jump in your car,'" said Brewer.

"It was like getting punched in the stomach and then some," said Marian Harris. "This has rocked our world. My kids are like, 'How does somebody do this?' How does this happen?"

The couple said they went to the clinic, found Sid and freed him.

State and local authorities went to the Camp Bowie Animal Clinic in the 5700 block of Lovell Avenue on Tuesday. Several of the animals there were seized as evidence in the investigation and placed in the custody of Fort Worth Animal Care and Control.

"I'm happy that something can be done and that people are listening, and that they can't get away with it no more," said Brewer.

Sid is home with the Harris family and being treated by other veterinarians. According to the Harrises' lawyer, doctors have determined he has mange, shows definite signs of being used for blood transfusions and shows evidence of being "abusively kenneled."

Neither the veterinarian nor anyone from the clinic has responded to NBC DFW's request for comment. Dr. Lou Tierce told the Star-Telegram the accusations against him are "all a bunch of hooey."

According to the Harris' lawyer the Texas State Board of Veterinary Medical Examiners will meet in Austin. Although a date hasn't been set, the case is being treated as an emergency.

An investigator from the board is meeting with Fort Worth police and the Tarrant County district attorney Wednesday morning to determine whether any criminal animal abuse charges will be filed.

The Tarrant County Health Department is also involved in the case due to the unsanitary conditions at the clinic, according to the Harris' attorney.