The Masked Dancer star Davina McCall wrote: ‘Sorry…that’s heartbreaking,’ and The One Show host Alex Jones commented: ‘So sorry!’
A follower said: ‘I remember being at one of your shows and you talking about him saying he was the only one who was pleased to see you when you came home, dogs give us the biggest joy and the biggest heartbreak when they leave, I feel for you.’
‘Nothing else is quite like this loss. I’m so very sorry,’ came another comment.
Said one follower: ‘Sending you all my love. We lost our beautiful boy 8 weeks ago, we feel completely lost without him’ as another simply said: ‘Pain like no other’.
Bilko regularly appeared on John’s Instagram page and the actor confessed it made him sad to see his best friend age.
Alongside a video of his pet curled up asleep on the sofa, John said: ‘This is my best mate Bilko.
‘He is 15 years old and has had a great life since we got him from a dogs home but it breaks my heart to see his legs failing on his walks.
‘But when he sleeps he still runs in his dreams . Sometimes we should all dream like dogs.’