This week a second inquest opened into the death of the Cannock toddler at Stafford Hospital in 2014. The disabled boy was taken into hospital two days after his third birthday for a pre-planned trial of a new feed solution, and his condition deteriorated over the next few hours until he died despite oxygen treatment.
A previous inquest which ruled that Jonnie died of natural causes was quashed after an independent doctor found that the milk he was given could have caused a reaction and led to his death.
Jonnie began suffering breathing problems, skin discolouration and vomiting in the hours after the feed started.
Yesterday the inquest heard from Lucy Preston, a senior dietician who knew Jonnie from when he was a month old and worked with his parents, John Meek and April Keeling, throughout his life on trialling different feed solutions, including the one carried out on the day he died.
Jonnie, who had the rare genetic condition De Grouchy Syndrome, was intolerant of many types of milk and could not keep most food down. He had trials of various amino acid-based feeds and for the final months of his life he was fed through a tube into his stomach.
Mrs Preston had conversations with his parents about the new feed in the days leading up to August 11, 2014.
She noted that April was nervous about setting Jonnie up on a new feed at home because of any potential issues, so she organised for April to bring him into the hospital on August 11, when paediatricians would be in the building.
April said that after checking in at the hospital, she was left alone in a room to set up the new feed. Mrs Preston told the inquest that she was wary of getting too close to Jonnie because she had a heavy cold that day, but on April's request she did check him.
She said that she noticed Jonnie's pre-existing skin condition but nothing else unusual.
"I couldn't see anything different from what I have seen on previous occasions," she said.
"I could see that April was worried and as I'm not a doctor I [went to get a doctor]."
That was shortly before 2pm, after the new feed had started at 1.30pm.
Jonnie was seen by doctors, nurses and specialists in the hours following as his condition deteriorated.
Lauren Tew, a support worker who attended the hospital with April and Jonnie, said that the two women struggled to get medics to come and see Jonnie when he was vomiting. Doctors did visit him and he was given oxygen treatment.
Mrs Preston said that her most likely conclusion was that Jonnie's breathing problems on that day and his eventual death were caused by vomiting or reflux, resulting in a foreign object entering his lungs (aspiration).
She said she saw no signs of an allergic reaction, like swelling, and that Jonnie had a history of vomiting and reflux.
Earlier this week, paediatrician Dr Ajay Gupta also said he did not see signs of allergic reaction.
The inquest continues and is expected to last three days in total.