Mr Whittington, 44, developed Type 1 diabetes (insulin dependent) aged 8, and was recently rushed to Hawke's Bay Hospital when his blood sugar levels rose alarmingly.
"The only two places I can't take Frodo are the zoo, because of diseases he might pick up from other animals, and Intensive Care - but I managed to get him into ICU at Hastings Hospital."
When he was moved to a ward for two days, Frodo followed.
"Everyone just warmed to him, and he was a huge comfort to me, word spread really quickly and when I moved, the first thing people asked was, 'where's the dog?'."
He was no trouble, as barking had been trained out of him. He stayed by his master's bed, and his toilet manners were impeccable - movements only brought on by fresh air and the command "busy, busy".
Endocrinologist Peter Mwamure had experienced guide dogs for the blind before, but never a hearing dog.
"There is a provision for this, and if it's going to help the patient from a holistic health point of view I don't have a problem with it," he said. "Frodo's presence did not stop us from meeting all normal hospital procedures with regard to safe practice."
A hugely positive reaction from staff and patients prompted Mr Whittington to think about becoming a Friend of the Hospital, visiting wards with Frodo to spread cheer.
"I went into the hospital to visit my sister yesterday. Patients were out in the hallway, you could see their eyes light up like a Christmas tree. I am going to start [regular visits] next week."
Since discovering Hearing Dogs New Zealand, a registered charitable trust based in New Plymouth, Mr Whittington had helped others to find their canine match and was an elected Hearing Dog speaker for Hawke's Bay.
Dogs of all breeds were considered for training, as long as they were friendly, intelligent and responsive to sounds.
Once qualified they wore a yellow jacket, and were provided free of charge to applicants who met strict criteria. People first had to prove they were capable of looking after the dog and show they formed a bond.
Two other Hawke's Bay people were Hearing Dog recipients, while another was on the waiting list.
See also: hearingdogs.org.nz for more information, or to donate.