A Tennessee mother said she was utterly blindsided when the pit bull she viewed as her 'best friend' mauled her so badly that she needed her leg amputated. 

Amanda Mears, 42, sustained the severe injuries while getting in the middle of a vicious encounter between two of her dogs on December 10. 

The single mom was getting ready to take her mixed Pit Bull-American Stafford, Dennis, out for a walk when her American Bully, Ralphie, escaped from a bedroom in her Murfreesboro home. 

Mears, a healthcare worker who often rescues dogs, noticed a few weeks ago that Dennis had been trying to attack Ralphie - who she has been fostering since July - so she had made a great effort to keep the two apart, she told the Daily Mail. 

When Ralphie rushed from the room, Mears quickly tried to separate the rivaling dogs - but Dennis was faster. 

In the blink of an eye, Mears said that Dennis lunged forward to attack. 

Fighting to keep Ralphie safe, Mears jumped between the canines, and that's when Dennis turned his aggression on her. 

He sank his teeth into her leg and unrelentingly tore through her flesh as the shell-shocked mother told her 10-year-old son to hide in his room. 

Amanda Mears was hospitalized after the brutal attack, needing her leg removed and surgeries on her hand and arm

Dennis, who the dog-lover described as her 'best friend,' was put down after the attack

She used her other leg to choke Dennis until he finally let go of her mangled limb. 

'I was a bit scared, but I've broken up dog fights before, and I didn't feel any pain because of the adrenaline,' Mears told The Mirror. 

'I ended up having to hook my right leg and my arms around him and choked him out to get him off me.'

Amid the chaos, Dennis also gnawed at her left hand and broke her right arm. Ralphie was unharmed. 

'Ralphie saved his own life by not defending himself,' Mears recalled to the outlet. 'As there was no one to fight back, Dennis got bored and eventually let go.' 

Mears described that her leg was 'hanging on by a thread' when emergency services arrived and took her to a Nashville hospital. 

However, since she had lost so much blood, the ambulance had to first stop at a closer hospital for a unit of blood.   

Once she arrived in Nashville and was stabilized, doctors broke the grim news that she would either have to lose her leg or undergo at least a dozen grueling surgeries to salvage it. 

Mears is a single mother who takes in dogs to rescue them from being euthanized