As any performer will tell you, preparation is key.

For Bridget, a role in Scottish Opera’s latest production means arriving at the Theatre Royal in Glasgow at least an hour before the show, leaving time for a snack and a snooze in her dressing room before she takes to the stage.

It’s the smallest of parts in the closing moments of Don Pasquale but then Bridget is the smallest of dogs – a chihuahua.

However, she has a huge amount of experience as a performer – including with Scottish Opera.

“Bridget played the part ten years ago,” says her owner, Denise Symon.

“Scottish Opera contacted us last year to say they were staging a revival of the show, and would Bridget like to take part. We immediately put it in the diary. They’re such a nice company to work with.”

Like most comic operas, the plot of Don Pasquale is complicated and silly, but one of the twists is that the cat-loving but allergy-suffering Don is tricked into believing he’s been given a cat, rather than a dog.

And who best to play the “cat” but a versatile doggy actor like Bridget?

Since she last played the role, Bridget has expanded her doggy dynasty.

Daughter Charlotte and granddaughter Rita are both backstage in her dressing room, with Rita her understudy.

Charlotte is officially retired but not before co-starring with Oscar nominated actor Paul Mescal in a music video for the American singer songwriter Phoebe Bridgers.

“You were in bed with Paul Mescal, weren’t you Charlotte?” says Denise, from Renfrewshire.

“It was written and directed by Phoebe Waller-Bridge [creator of Fleabag] – who was so taken with Charlotte she wanted to make a film with her.”

Denise is prepared for any last-minute nerves, or indeed any doggy mishaps.

“They’re dogs, we can train them, but we can’t control them. All we can do is make sure they have good temperaments and keep them relaxed, but dogs will be dogs.”

Yet it takes a lot to phase Bridget.

“She couldn’t care less. She has been known to be side of the stage, in my arms, with her eyes shut.”

Her motivation as an actor is simple – it’s all about the snacks.

“What’s in it for me? What’s my reward for being here? It’s all part of the training. We need to show them it’s a good positive place, and that they like everyone they’re working with and they get rewarded. In Bridget’s case, for staying awake.”

Baritone David Stout is happy to flout the old rule about not working with children and animals.

With three children under the age of nine at home, and a degree in zoology, he couldn’t be more qualified to share the stage with Bridget.

“I love animals, always have done, and a long time ago I was a trainee safari guide in Botswana so for me it’s fairly natural. We’re very lucky to have such a well-behaved little lady as Bridget, who comes on in the closing scene.”

There’s a roar from the audience when Bridget is brought on in her cat costume – and presented to Don Pasquale. The briefest of bows and she’s back in the wings for a snack.

Back in the dressing room, Charlotte is barking her disapproval at Bridget’s absence.

“She’s the attention seeker,” says Denise.

“She doesn’t like it when she’s not at the centre of things.”

Hopefully nobody has told her that it’s only Bridget and Rita who’ll be joining Scottish Opera for the rest of the Glasgow run, and then on tour in Edinburgh, Inverness and Aberdeen.

Stage door is busy with family and friends of the singers and musicians, but Bridget gets her fair share of fans who want to shake her paw and wish her well.

Denise signs her charges out with three tiny pawprints, and it’s time to go home for a late dinner, ready to do it all again at the next performance.