You also might try limit ingredient from Natural Balance. Try the Duck and Potato, I use the small bites. Also switch slowly. That said, I change food every 3 to 4 weeks and have always done so. My Basenjis are very used to change so I never have to worry about changing food or what I add (veggies/fruits, etc). Adding pure pumpkin is a good thing too as noted by elbrant. Have you spoken to your Basenji's breeder? Are you feeding or where you feeding what they fed? I also do not use puppy food either in raising a litter of pups and do not recommend that new owners use puppy food either. If you are using a good quality well balanced kibble, puppy food is not necessary
https://www.naturalbalanceinc.com/dog-formulas?gclid=COaD3M_31-MCFcOmxQIdTrAL6w&gclsrc=ds