I don't have experience with my Sophie Kate losing teeth (yet), I do brush her teeth a few times a week and I check them a lot. I need to ask the Vet to look at them next time we are there to make sure they are still clean but they sure do look white. As far as changing her toothbrush, I use the same one for about 6 months okay maybe a little longer but I do not change it monthly.
I do have experience with my Cat Avery losing teeth. He is 14 years old and went in December and had his teeth cleaned (probably will be his last). Poor Avery had 4 teeth he had to have pulled. After that he started losing weight, I took him to the vet and we tested for everything and found nothing wrong so we decided to switch him to really tiny kibble and wet food.
__________________ Cheryl,Mom to  SophieKate |