Since donations have flooded in, Ritchie shared a message on the owners' behalf.
"The owners are so overwhelmed with the support and are grateful that there are still awesome people out within the community," she wrote.
Speaking to the Herald previous, Jeffrey Rapana, 19, recounted what happened when he found out the devastating news.
He said he had just pulled into the driveway of his Pukekohe home, when he saw his partner standing outside visibly upset.
"She said 'I think I found Simba'," Rapana told the Herald.
"I just started bawling my eyes out because I knew something had happened to him.
"She mumbled to me, 'I think he has no head'."
Hera Ratahi, 19, found the body of their beloved pet dog - in a scruffy condition and beheaded - discarded in a creek on Kayes Rd.
They had looked after the pitbull since he was a puppy.
"I don't know how someone could do that," Rapana said.
The couple had feared the dog was stolen, a suspicion that has only grown since they found Simba's body.
Simba went missing on February 19, shortly after he had been let outside to relieve himself.
Ratahi heard Simba make a "weird bark" and shortly after went outside to look for him but he had vanished.
The dog had been like a best friend to Rapana.
"We were looking for him every single day for two weeks," he said.
The couple are urging people to come forward with any information about the dog's disappearance or death.
"We want to know who did it," Ratahi said.
"Whoever did it doesn't deserve to be walking around today. They should be put away."
An SPCA spokeswoman said an investigation into Simba's death is now closed.
The SPCA would not give any further details.
The spokeswoman previously said the organisation didn't believe there was any foul play involved.
