It depends on the individual dog and how well their teeth are taken care of at home. Yorkies tend to need them more often and can have tartar build up after less than 6 months while other may need very few in a life time.
As long as you brush often, feeding soft food isn't a problem. In fact, no matter the diet, their teeth should be brushed.
Ellie hasn't had one in 16 months and her vet said her teeth look excellent.
__________________ Crystal  , Ellie May (RIP)  , Rylee Finnegan  , and Gracie Boo🐶 |