Teach your pets to love having their teeth brushed

ALWAYS GO AT YOUR PET'S PACE - ALWAYS REWARD GENEROUSLY

Going at your pet's pace means to assess after every single repetition whether that was easy for your pet (then you can increase difficulty slightly) or neutral (then you can do the same repetition again) or hard (then you need to make it much easier next time). When increasing difficulty, always just increase one part, so for instance don't go longer and reach other parts of the mouth at the same time. It can even be helpful to go shorter when increasing difficulty at another end.
Keep your training sessions short and sweet and always end on success - that can literally be the presentation of the toothbrush on a meter distance and giving a treat for that. Success doesn't have to look fancy.

You know your pet well and can tell when they are happy, neutral or agitated. If you see stress/avoidance signals go back a few steps. For dogs for instance look out for whale eye, lip licks (that aren't toothpaste related), ears back, pulling away, ignoring you, yawning. Learn more about dog body language here. For cats look out for instance for tail twitches, dilated pupils, tight ears, leaning or moving away.

Relaxed body language and voluntary participation is what we are looking for!

STEP 1
Gently stroke the outside of your pet’s cheeks with your finger only (no brush) and slowly lift the lip for just a couple of seconds. Reward generously afterwards. Over the course of a few days build the duration up to about 30 seconds.

STEP 2
Repeat as above and also place a small amount of toothpaste on the end of your finger and let your pet sample it. Remember to reward generously.

STEP 3
Repeat Step 2 but this time gently run your finger or finger toothbrush and a small amount of toothpaste over your pet’s teeth for just a couple of seconds. Over the course of a few days build the duration up to about 60 seconds. Reward generously.

STEP 4
Repeat Step 3 of running your finger or finger toothbrush over your pet’s teeth and work on reaching less obvious parts of their teeth. Reward generously.

STEP 5
Present the toothbrush and reward. Over the course of a bunch of repetitions go closer to your pet's mouth with the toothbrush. Always reward and remove and then start over. Work your way up to lift the lip for a couple of seconds while presenting the toothbrush and eventually touching the teeth for a couple of seconds. Over the course of a few days build the duration of touching the outside of the teeth up to about 30 seconds. Reward generously.

STEP 6
If all is going well run your finger over all the teeth for 20 seconds and then gently insert the brush and again run over teeth for 30 seconds increasing the areas that you reach to. Reward generously.

STEP 7
Work up to spending at least one minute on each side of the mouth brushing your pet's teeth. Reward generously. Celebrate your awesome pet and yourself for being such an awesome training team!