Recently, Mad Men actress Christina Hendricks split with her husband, actor Geoffrey Arend. They released a charmingly optimistic joint statement: ‘We will always be grateful for the love we’ve shared, and will always work together to raise our two beautiful dogs.’

It’s a lovely thought but there’s generally only one person shrugging on a coat at 10pm and heading into a howling gale to supervise pre-bed wee-wees – and that’s the one who gets the residency order. The ex might get the occasional visit for a cuddle, but they’re not going to have to be up at 4am with a vomiting cat. Nor are they going to benefit from the sheer joy of living with pets, absorbing the adoring comfort of dogs who know you’re sad, or the admirable indifference of an ageing cat who wants to sleep on your head.

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In the first flush of love, when it’s too soon to commit to a baby, many couples opt for a puppy instead - often overlooking the fact that dogs live around 14 years, longer than many ill-fated marriages. Last year, Ant McPartlin and his wife, Lisa Armstrong, split, with their chocolate lab Hurley proving the main difficulty. We still share quite evenly. Hurley’s welfare comes first and we both love him very much,’ said Ant, some months later.

Equally committed to their rainbow family of multiple canines are Jennifer Aniston and Justin Theroux. When they broke up last year, there was talk of shared custody of their four dogs, but, with Jennifer in LA and Justin in New York, regular Sunday visits proved impossible. However, when Dolly (living with Jennifer) died recently, the couple “reunited to mourn”, with Justin posting a picture of them together at the dog’s funeral.

Not everyone is so amicable – which is why some couples even demand prenups for pets.

Jennifer Curtis, a partner at Maguire Family Law, in the UK, says: ‘We’re seeing a growing number of divorce cases where people are arguing over the future of their pets. A third of pet owners think animals should be treated the same as children when it comes to break-ups, but the law doesn’t agree.’

A pet prenup is a wise move, she advises. ‘It deals with common issues like ownership; and arrangements for future care of the pet, providing certainty in case the parties separate.’

‘Dogs are very connected with humans,’ says Sue McCabe, a dog behaviourist. ‘They read our emotions and understand if we’re stressed. If the person who is leaving the family home is their primary carer, it can be very upsetting. Like us, they grieve and will feel depressed.’

This potential guilt-bomb can be defused. ‘Pet parents should try to come to an agreement where both partners still see the dog and have an ongoing relationship, so their emotional needs are still met,’ she says.

And just as divorcing adults are urged to be amicable for the sake of the children, McCabe adds: ‘Whatever the circumstances, I would urge people to be mindful of the dog, and avoid shouting. Make sure the dog is kept busy and try to do something every day that makes them happy.’