"Many commercial kibbles containing the herb rosemary may, in a few cases, lead to seizures." Healthy Adult Diet
The small amount of rosemary in kibble probably isn't go to trigger a seizure in a healthy dog. The problem is when many foods and treats containing rosemary are fed, making the total amount consumed much higher.
Did you know that Petzlife contains Rosemary?
PetzLife Products Inc - Products For a Healthier Pet
It's important to read your labels.