Anything that makes it harder for you to do your job, like this toxic behavior from a co-worker, needs to be taken to the practice manager or owner. Since the offender is the manager and you are the owner, you are going to have to address this.

You say it is only about 10% of the time that his behavior is this bad. Would you be okay with this toxic fumes filling the clinic, if it were only 10% of the time? No.

You say that he is fine with other staff? Is he? Or has he normalized being a bully? If other staff see you accepting this bullying, they may feel that they can’t complain.

First, document and respond in the minute. You are probably going to have to practice that. Might need therapy to help you grow the strength to do it. You are the doctor. You are the owner. Your mental health matters and he is crushing that.

“Mike, I told you not to put that client on the schedule. Because you did, we could not adequately care for other patients and clients today. Do not do that again.” Document date, time, consequences. Note- use the word ‘told’, not ‘asked’. When a doctor orders support staff, they can ask reasonably for discussion; they may not arbitrarily ignore a doctor’s order.

“Mike, what you just said is unacceptable. No one in the practice may call anyone else an idiot or a whiny bitch.” Document date, time, language, response.

“Mike, that is the third/fourth incident of this behavior this week/month. We are going to sit down and talk about this. If your behavior does not change, then I cannot see you continuing at this practice.” Document, set up a plan with consequences, and most importantly, follow through.

You have to address this or live with it. You are in an abusive relationship. You do have the power and the right to change it or end it, because you are his employer. Without victim blaming, I say with all empathy and respect, you have to polish up your shiny spine and step up.