It’s seven o’clock in the morning and from the kitchen I can hear the spring sound of birds.

Or, rather, the springing sound of one particular bird that is squawking and chirruping and springing from the roof of our extension to our neighbour’s and then back again.

I open the back door and see a demented starling doing her very best to convey to something or someone that she is a very angry bird indeed.

Although there is no sign of her audience, I’d be willing to bet my holiday deposit that it’s Charlie, our agile little black cat who has a penchant for anything smaller than a rabbit that moves, and particularly for the ones that can do that clever flying stuff.

But unless he’s actually on the roof tiles two storeys up, he appears to be blameless this time. I go back inside and get on with breakfast, and forget about the starling.

That night, when I get home, our big fat female cat whose chosen lifestyle is morbid obesity waddles in as normal to greet me.

Charlie, who usually does a pirouette over her slow back and completes a top-to-toe bath before she manages to reach the couch, is nowhere to be seen. And then I spot him in the utility room, gallantly trying to move towards me, but is dragging his right back leg as if it’s a foreign object he can’t shake off.

The vet sees us pretty well immediately. It’s a painful examination for all three of us in different ways, but the diagnosis is almost certain.

Charlie has probably either fallen or jumped from a very great height. No, not just from the garden fence A great, great height. It could even be from a rooftop. A bit of me takes my hat off to that plucky mother starling for defending her nest.

But then I think about the damage. He has completely torn his Achilles heel, the vet explains. And the damage? I ask. I won’t put his reply in sterling, in case my husband or bank manager ever read this, but expressed in an alternative currency it’s a week in a villa in Mallorca or two weekends away at a Michelin starred hotel, including wine and car hire.

Obviously, I’m quite prepared to pay up if needs be. But let’s get a grip first.

Is this bad? I ask the vet. Privately, I think it sounds like the sort of thing that athletes whinge about to get out of running marathons.

The vet looks at me quizzically, as if the entire country knows what a torn Achilles tendon is. I’m obviously not reading enough medical journals. So it’s going to mean an X-ray, two operations, a screw and pin to keep the leg stretched out, and cage-rest for two months.

Cage-rest basically means siting a cage about the size of an operating table in your living room, stocking it with a bed, food bowl and cat lit tray, and counselling one of the liveliest cats in Christendom for eight weeks on the wisdom of moving as little as possible.

The main problem initially will be negotiating the cat lit tray, says the vet cheerily. There will be accidents in the first few weeks as he tries to work out what to do with the pinned leg.

Honestly, that won’t be the main problem. There will be several main problems, like steeling ourselves against the howling of a miserable imprisoned cat. And persuading my husband that it’s perfectly acceptable to be preparing and cooking food while a cat three feet away completes his daily ablutions. Oh, and you know that money we’d put away for an early summer break…?

I go home to move furniture and ring the man in question. I start with the diagnosis.

“Ha, well, that rules him out of the England squad,” he laughs. Sometimes the man is incomprehensible.

You wait till I tell you about the cage, I think, as I pause for him to stop laughing at his own joke.