hi, new to the forum. Advice on dog debt

[Meemo]

My son was in a +1 year relationship when the lady unfortunately suffered the death of her dog, he comforted her during this time, then she decided she was going to buy a puppy a few weeks later. They went to view the pups and came away with one as you do, my son offered to go halves with her on the cost of the dog so they each put in £850 and continued to share the food and insurance costs. the relationship has since broken down, and although it has been a stretch my son has been able to collect the dog on occasions and continued to contribute as before but has now realised it isn't a sustainable position and they should agree to one buying out the other. She isn't entertaining the notion of my son owning the dog outright, but hasn't offered any payment or payment plan for her to buy his share, all the time continuing to message him for contributions to the food and insurance assuring him that they will sort it out. Any advice to nudge it into a solution or of the legal stance here? no contract exists but all the transactions are detailed as "puppy" from his bank account.
thanks

[Scot22]

Wonder if she is still trying to cling on to the relationship.

I suggest sending a formal letter, recorded delivery, stating your son will contribute for a maximum of two weeks for a solution to be found. It is obviously a pedigree dog to be able to find a buyer unless she makes a reasonable offer to your son. Make sure all communication is recorded.

[Meemo]

This was my thought initially. But will certainly send a letter see if that helps. I had already told him that once they agree repayments I will draft up a schedule for her to sign, fingers crossed. Thanks for your advice