Under the dispassionate eye of divorce law, dogs are considered "chattels" – unlike children, the court won't decide where it is in their best interests to live post-split – they are simply treated as shared goods.
But, as a raft of recent celebrity break-ups has highlighted, it's no good packing up the terrier along with the broken radio alarm and the back copies of Wired. While a Marie Kondo-style decluttering of possessions may be welcome, almost nobody wants to say goodbye to their beloved pets.
This week, Mad Men actress Christina Hendricks split with her husband, actor Geoffrey Arend. They have 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".
• The Ex-Files: When should you get a prenup?
• Divorce lawyer's top prenup tips: Protect your Tupperware
• Are prenup agreements a good idea? Would you get one?
• $26m Lotto winner Trevor Cooper's marriage break-up: 'There was no prenup'
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, or lugging giant bags of kibble to the checkout – 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 like a Russian hat.
When I split up with my ex in 2014, I got custody of our two rickety old cats, and – while the intervening years have not been kind (one died, and the other is so old he lists like a galleon in a storm when he stands up) – their presence has been a delight and consolation. My current partner and I now share a beloved spaniel, and I can't imagine the agonising tug of love, should we ever split (hence, we can't).
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 trips to McDonalds proved impossible.
However, when Shepherd-mix 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, though – which is why some couples even demand prenups for pets, legally stating who will get Fluffpot and Tubbs in the event of a breakup.
Jennifer Curtis, a partner at Maguire Family Law, 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 unfortunately the law doesn't agree," she adds. "Obviously, the emotional attachment to pets can be huge, which is why we see so much upset over who gets to keep them."
A pet prenup is a wise move, advises Curtis. "It deals with common issues like ownership; and arrangements for future care and maintenance of the pet, providing certainty in case the parties separate."
But while A listers like Johnny Depp and Amber Heard were able to work out who got custody of Pistol (dog, rather than item, fortunately), thanks to their legal teams, those of us with less cash are left to work it out between us – which means putting the pets' needs first.
"Dogs are very connected with humans," says Sue McCabe, dog behaviourist at Muttamorphosis. "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."
Photo of a woman smiling, sitting on a bench with a dog on her lap
Dog behaviourist Sue McCabe says dogs can feel depressed when their owners split up.
This potential guilt-bomb can be defused, however – "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."
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."