Your puppy arrives already used to one food, one set of meal times, and the rhythm of the breeder's home, and in the first days everything else about her life has changed too. Changing her food and schedule on day one stacks digestive stress on top of settling-in stress. The fortnight gives you a calm runway: hold what the breeder did steady while she learns your house, then move food and timings across in small steps she can absorb without loose stools, skipped meals, or a confused body clock.
Days one to three: change nothing about food
Feed the exact food the breeder sent or named, in the amounts and at the times she is used to, even if your long-term plan is different. Ask the breeder before collection how much she eats at each meal, how many meals she has, and when the last evening feed happens, and write it down. A puppy who eats familiar food on a familiar clock in a new home has one steady anchor while she figures out new people, new smells, and new sleeping arrangements. Keep treats minimal in these days so her stomach has nothing extra to process and you can read her normal appetite clearly.
The middle of the fortnight: blend the foods
Once she is eating confidently and her stools are firm, begin mixing your chosen food into the breeder's. A gentle pattern is roughly three quarters old to one quarter new for a couple of days, then half and half, then one quarter old to three quarters new, watching her droppings and enthusiasm at each step. Loose stools, lots of wind, or food left in the bowl mean you moved too fast — drop back to the previous ratio for another day or two rather than pushing on. Keep total quantity steady as you blend so you are changing the recipe, not the amount, and shift meal times toward your household's times by fifteen minutes or so at a step rather than jumping an evening feed by two hours overnight.
The end of the fortnight: land your routine
By the close of the second week she should be fully on your food at your times, with the number of meals suiting her age — very young puppies still need their day split into several small meals rather than one or two large ones. Settle the routine where it will actually live: who feeds in the morning, where her bowl goes, and how long food stays down before uneaten food is lifted. Note when she finished the transition and how her stools responded, because that history is genuinely useful if she later has a digestive wobble and a vet asks what she eats and when it changed.
If the transition stalls
A puppy who refuses the new food but happily eats the old is usually telling you the pace or the temperature of the food is wrong, not that she is stubborn — try a slower blend and serve the new portion slightly warmed to release its smell. A puppy who stops eating altogether, has repeated vomiting or diarrhoea, or seems flat and uninterested in play in these early days needs a vet check promptly, since young puppies can go downhill quickly and a new home is exactly when parasites or infections picked up before arrival may show themselves.
Getting the whole household to mix the same ratio on the same day is the fiddly part of a fortnight switch, and KinsLe Care Teams helps by holding the daily blend and meal-time duties for this puppy in one place, with each feed marked done so nobody guesses.