We give her 10 drops 3 time a day as vet recommended .How long will it take for milk thistle to help my 11 year old yorkie? With liver disease

Your vet can better answer this question. However, milk thistle, also know as St. Mary's thistle, doesn't necessarily cure liver disease. It helps the liver to fight toxins and other issues but the key word is helps. At 11 years of age your Yorkie is a senior and may awys have an issue.

I would think the doc prescribing you the medication would have told you the time limit of seeing results. Results for any medicTion is about 14-30 dAys, maybe even 60 days for the body to react to the meds.

If you want to know, contact the vet who prescribed the medicine.