French veterinarians are authorised to both prescribe and deliver drugs. This situation of conflict of interest is sometimes denounced as a potential source of over-prescription and overuse of veterinary antimicrobials, even if no evidence is available up to now. This leads to regular calls for separating prescription from drug delivery, even if the consequences of such separation are unknown. The present work aims at describing the business model of French veterinary offices and the expected impact of separation on those offices. A dataset of 15 million observations was built with structural and accounting data collected for the period 2015-2017 from French mixed veterinary offices. Results of the baseline scenario indicate that veterinary offices' profit generated from farm animal activities is mainly driven by drug delivery (about 70%), while profit from companion animal activities is mainly driven by medical acts (i.e., consultation and advice, surgery, and laboratory analysis) and sale of accessory products (about 65%). The net margin rate is higher than 25% for all activities, except for material selling. If drug delivery or sales associated with a medical act (same day, same client, and same animal) do not require additional human resources (alternative scenario), the net margin is reduced for medical acts. For both scenarios, a high variability is observed between veterinary offices. This shows that the profit of each activity is highly driven by time spent on the activities. Our results suggest that, in the case of restrictions on drug delivery by veterinarians, their profit may dramatically decrease, especially for farm animal practitioners and those with low medical acts profitability. Further work is needed to account for the high diversity of situations faced by veterinary offices and the sensitivity of their profitability to production costs.