When it considers necessary, the department shall furnish antirabic (human) vaccine to the physician attendant upon persons bitten by or otherwise exposed to a pet or other animal found or suspected to be affected by rabies. If the department considers it necessary to provide antirabic (human) vaccine to the persons bitten or otherwise exposed to a pet suspected of or having rabies that has not been vaccinated, the pet owner shall reimburse the department for the cost of the vaccine. Reimbursement is due the department within thirty days after billing.