She said she was devastated her son had been hurt.
"I just can't believe it."
Mr Skinner said Caleb was a fighter but he was concerned about the toddler's current condition.
"He's normally so full of life. It's just devastating."
Along with the head injury, Caleb had bruises over his entire body, Mr Skinner said.
"He's sedated because there is too much bleeding from the brain at the moment. He's on machines which are breathing for him ... it's not good."
When Caleb was first taken to hospital he responded for a short time, touching his nose and trying to reach out, his father said.
"It hasn't been good since then."
Hospital visits are not unknown to the toddler, who has undergone surgery more than once for a bowel condition he was born with.
A friend of the family claims Child, Youth and Family ignored calls from him last week with concerns about the child's care.
Masterton Advocacy Service co-ordinator Trevor MacKiewicz told the Times-Age he raised concerns with the toddler's mum on Friday when he noticed scratching and bruising on the boy's face.
She told him their dog had caused the injuries but Mr MacKiewicz said the explanation didn't appear to fit with the injuries so he called the child protection agency.
However, he said he felt dismissed by the call taker and now wished he had made her listen.
"I didn't give Joanne's explanation much weight. I was rushed off my feet at the time. I rang CYFs to see if they could do anything. They weren't interested and felt the explanation was probably genuine. That it was a minor incident with a legitimate explanation ... we wouldn't be dealing with this now if they had listened. It's such a shock to everyone ... the last thing I wanted was to see this happen."
Child Youth and Family general manager operations Marion Heeney said staff were saddened to learn Caleb had been seriously injured.
"Our thoughts are with his family and those who love him."
All calls to the agency's call centre were recorded but despite a search of records, they had not found Mr MacKiewicz's call, Ms Heeney said.
"Nevertheless, we are in contact with the alleged caller to get more information as we want to get to the bottom of this."
A 39-year-old Masterton caregiver appeared before Judge Tom Broadmore in Masterton District Court yesterday afternoon on a charge of assaulting a child. He was wearing a police-issue boiler suit and stood staring towards the front of the courtroom throughout his appearance.
Judge Broadmore granted interim name suppression and the man was remanded in custody by consent. He is due back in court on March 17 to plead to the charge.