附录 99.3

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Security Class 持有人账号 代理表——将于 2023 年 6 月 28 日举行的年度股东大会本委托书由管理层代表管理层征集。 代理注意事项 1.每位持有人都有权指定自己选择的其他人或公司出席会议或任何 休会或延期会议并代表他们行事,这些人不必是持有人。如果您希望任命除管理层提名人之外的个人或公司,其姓名已印在此处,请在提供的空白处插入您选择的代理持有人的 姓名(见反面)。 2。如果证券以多个所有者的名义注册(例如,共同所有权、受托人、遗嘱执行人等),则所有注册的人都应签署此委托书。如果您代表公司或其他个人投票 ,则可能需要提供文件,证明您有权在规定的签名能力下签署本委托书。 3。该代理的签名方式应与代理上显示的名称完全相同。 4。如果未在本委托书背面提供的空白处插入日期,则该日期将被视为代表管理层将其邮寄给持有人的日期。 5。该代理人代表的证券将按照持有人的指示进行投票,但是,如果没有就任何事项做出这样的指示,并且代理人任命了反面列出的 管理提名人,则该代理将按照管理层的建议进行投票。 6。根据持有人 的指示,本代理人代表的证券将在可能要求的任何投票中被投票赞成或拒绝投票,或对本文所述的每项事项投反对票(如适用)。如果您已就任何有待采取行动的事项指定了选择,则将对证券进行相应的投票。 7。除非法律禁止,否则本委托书授予对会议通知和管理信息通告中确定的事项的修改或变更或可能适当地提交会议或任何休会或延期的其他事项的自由裁量权。 8。本委托书应与管理层提供的随附文档一起阅读。 提交的代理必须在 2023 年 6 月 26 日美国东部时间下午 4:30 之前收到。 每周 7 天 24 小时使用电话或互联网进行投票! 使用电话投票 • 用触摸 电话拨打下面列出的号码。 1-866-732-VOTE (8683) 免费电话 使用互联网投票 • 访问以下网站: www.investorvote.com • 智能手机? 扫描二维码 立即投票。 以电子方式接收文件 • 您可以访问 www.investorcentre.com 注册接收未来的安全持有人 的电子通信。 以虚拟方式参加 会议 • 您可以通过访问此 文档背面提供的 URL 来虚拟参加会议。 如果您通过电话或互联网投票,请勿将此代理人邮寄回去。 邮寄投票可能是以公司名义持有的证券或代表他人投票的唯一方法。 通过邮件或互联网投票是持有人可以任命除本 代理背面提名的管理层提名人以外的个人为代理持有人的唯一方法。您可以选择上面概述的两种投票方法之一来对该代理进行投票,而不是邮寄此代理。 要通过电话或互联网投票,您需要提供下面列出的控制号码。 控制号码 ------- Fold ------- Fold

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------- Fold ------- Fold Appointment of Proxyholder I/We being holder(s) of securities of Cardiol Therapeutics Inc. (the “Corporation”) hereby appoint: David Elsley, or failing this person, Chris Waddick (the "Management Nominees") OR Print the name of the person you are appointing if this person is someone other than the Management Nominees listed herein. Note: If completing the appointment box above YOU MUST go to http://www.computershare.com/cardiol and provide Computershare with the name and email address of the person you are appointing. Computershare will use this information ONLY to provide the appointee with a user name to gain entry to the online meeting. as my/our proxyholder with full power of substitution and to attend, act and to vote for and on behalf of the holder in accordance with the following direction (or if no directions have been given, as the proxyholder sees fit) and on all other matters that may properly come before the Annual General Meeting of shareholders of the Corporation to be held online at https:// web.lumiagm.com/419302032 on June 28, 2023 at 4:30 pm, Eastern Time and at any adjournment or postponement thereof. VOTING RECOMMENDATIONS ARE INDICATED BY HIGHLIGHTED TEXT OVER THE BOXES. 1. Election of Directors 01. David Elsley For Withhold 02. Jennifer Chao For Withhold 03. Michael Willner For Withhold 04. Colin Stott 05. Peter Pekos 06. Dr. Guillermo Torre-Amione 07. Chris Waddick 08. Teri Loxam 2. Appointment of Auditors To appoint BDO Canada LLP, Chartered Professional Accountants, as auditors of the Corporation and to authorize remuneration to be fixed by the Board. For Withhold Signature of Proxyholder I/We authorize you to act in accordance with my/our instructions set out above. I/We hereby revoke any proxy previously given with respect to the Meeting. If no voting instructions are indicated above, and the proxy appoints the Management Nominees, this Proxy will be voted as recommended by Management. Signature(s) Date Interim Financial Statements - Mark this box if you would like to receive Interim Financial Statements and accompanying Management’s Discussion and Analysis by mail. Annual Financial Statements - Mark this box if you would like to receive the Annual Financial Statements and accompanying Management’s Discussion and Analysis by mail. Information Circular - Mark this box if you would like to receive the Information Circular by mail for the next securityholders' meeting. If you are not mailing back your proxy, you may register online to receive the above financial report(s) by mail at www.computershare.com/mailinglist. D T P Q 3 5 3 9 6 0 A R 1