[Maximo]

Welcome to Yorkie Talk. Using a silicone product once should not cause a lot of damage. You can use a clarifying shampoo.

Now that she has turned 1, is her hair longer than it was in the past? I noticed on my boys that the longer their hair grew, the more 'difficult' it was to brush. Brushing requires more care, gentleness. I can't just put the brush at their topline and start pulling down.

I do line brushing and combing, taking small sections of hair and working on them individually. I hold the section with one hand and work the brush or comb with the other hand. I start at the ends of the hair and work my way up. This prevents skin pulling and damage to the hair.

When I encounter tangles, I carefully pick them apart and work the brush or comb gently. If I were to just brush the way I do my own hair, a lot of my dog's coat would come out on the brush.

I never brush when the hair is soaking wet. I use fingers or a very wide tooth steel comb only. Never pull on wet hair.

The longer the hair, the more susceptible to damage. My boys are really hard on their coats by snuggling in beds, dragging in grass and on pavement outdoors, and carpet surfing when we play fetch.

If none of this helps and she is still having a lot of hair breakage, I would be inclined to ask my vet to assess the coat and skin.