9.17am, Tuesday 26 May: No less than three vets are concentrating on Assisi’s surgery – including our friend Dr John Wu from Guangzhou (wearing purple), just coincidentally on site to see our bears, but happy to scrub in.

Assisi is the second-to-last bear of our 10 survivors from the bear farm in February to have his cholecystectomy (removal of damaged gall bladder), and is also undergoing castration and removal of three badly broken canines (resulting from frustrated bar-biting on the farm).

In truth, we've been worried sick about this beautiful bear. Just a couple of weeks ago, he had a scan after vet Heather and team picked up a mass in his chest on the X-ray.

UK radiologists interpreted the scan, confirming the mass in his chest, and explaining that it could be one of two things: dilation of his aorta (large vessel leaving the heart), or a tumour inside the walls of the aorta.

As Heather summarised, either of these conditions is essentially untreatable, has a poor long-term prognosis in other species and would generally be a case for euthanasia. However, during our years of working with these rather incredible bears, we've learned that they are remarkably resilient and can often tolerate conditions that would prove fatal for other animals.

Indeed, one of our biggest frustrations is when one of our rescued bears doesn’t get to walk on grass – when we lose him or her to diseases such as liver cancer before they’ve had their day in the sun. So for every bear with a "chance", we carefully consider the options from both medical and welfare perspectives and make the best decisions we can.

Consequently, bears with various conditions whose pain we can “manage” and minimise, are given their chance and carefully observed while living in their grassy enclosures, enjoying happy days out with their friends.

And Assisi deserves his chance. We've all agreed that as he is showing minimal clinical signs, and has already survived a fistula surgery (or butchery) on the farm and a health-check with us, the surgery to remove his gall bladder and ongoing rehabilitation is well worth a shot. We will hold on to our dream of seeing him play on grass until the day we all sadly acknowledge that his borrowed time has run out.

This decision was also well-received and agreed on by his generous sponsors, Bob Kerridge and his team at the New Zealand SPCA, who also have been praying for this bear since he first arrived. Bob and staff have been nothing short of wonderful to our bears over the years, spreading the message of their plight on the farms and raising funds that help in the ongoing course of our work.

Choosing from our last arrivals in February of this year, a bear we nicknamed “Hamster”, seemed to be just right for “their” bear. He was so called because after arriving from the farm, he carefully pulled down the straw we placed on top of his barbaric cage, piece by laborious piece, until he’d crafted what was obviously the perfect bed – and curled up comfortably to sleep.

Even standing up in those early days after arrival must have been torture for this bear, as two of his claws had grown around into a circle, painfully puncturing his pads. The stench from this injured rotting flesh was nauseating, and the years of incessant, throbbing pain must have been hard for him to endure. Here he is on arrival, his neglected claws clearly visible:

Today, the SPCA’s chosen name, “Assisi” – after Saint Francis of Assisi, the Patron Saint of Animals – seems just perfect for this brave and gentle bear.

10.10am: Looking at Assisi now on the table, breathing well and stable under anaesthetic, we’re all holding our breath in hope. The various procedures are being performed simultaneously to minimise the length of time he has to spend on the table and on the gas.

Our fabulous nurses, Caz and Wendy, and volunteer Kelly are busily monitoring the anaesthetic, spinning the bloods, taking samples of the gall bladder for the Chinese pathologist who is working with us to analyse, giving drugs, replacing drips, and keeping Heather, Jen and John supplied with sterile instruments, blades and suture materials, as Assisi sleeps on.

11.02am: The gall bladder is out and, surprisingly doesn't look too bad, although Heather has found some scarring on his liver which originated from the surgery on the farm. Still, as she says, the liver can rejuvenate itself well and she doesn't expect any long-term problems there.

Jen has already removed two of his broken teeth, and is working on the third – and Assisi is now also missing two little organs at the other end of his body, now that his castration is also complete. Somehow it seems safe at last to breathe.

Last week I spent some time with this long and lovely bear, enjoying how bright and curious he was, as he greedily bolted down a selection of fruit with all the enthusiasm of a fully fit bear.

His lemony moon-shaped crescent is glorious and runs into a shawl on his shoulders, and he would also have beautiful "Mickey Mouse" ears if they weren’t cut off at the ends (perhaps bitten by another bear on the farm when their cages were placed too tightly together).

And throughout this adoration, Assisi played the ravenous bear-card to perfection, scrounging extra fruit just by looking in our direction with those soulful, melting, brown eyes.

12.30: Assisi is off the gas and now being wheeled into the recovery room where lovely volunteer Lucy will sit with him until he is awake and standing on all fours. Within a couple of days, fingers crossed, he'll be feeling much better, and his surgery scars will be well on their way to healing.

Until then, tender, loving care – and heaps of it – is the order of the day, as together we all pray for this saint of a bear to be well.