All licenses shall expire annually on December 31 of each year but may be renewed by application to the board showing fulfillment of continuing education requirements and payment of a renewal fee established and published by the board. The continuation of practice after the expiration of a license shall be in violation of this article and be cause for suspension of the license. The executive director shall send a reminder of expiration 30 days prior to expiration by first class mail and issue a new display license to all persons registering under this article. Failure to renew a license on or before January 1 of each year shall prompt the executive director to send a final notice of expiration by certified mail, return receipt requested, to the last address of the veterinarian known to the board and a late penalty shall be assessed and the license shall be suspended for non-renewal. A person may renew a license suspended for non-renewal at any time within two years, upon application, payment of the prescribed renewal fee and a late penalty fee per year for late renewals, provided the applicant is otherwise eligible for renewal. The board may renew a license without fulfillment of the continuing education requirement to any nonpracticing veterinarian over 70 years old or grant extensions or exemptions of continuing education requirements for veterinarians with extenuating medical or other circumstances.