Exhibit 15.4

Tel: 514-931-0841
Fax: 514-931-9491
www.bdo.ca BDO Canada s.r.l./S.E.N.C.R.L./LLP
1000 De La Gauchetière Street West
Suite 200
Montréal, Québec H3B 4W5

Consent of Independent Registered Public Accounting Firm

Cardiol Therapeutics Inc.

Oakville, Canada

We hereby consent to the incorporation by reference in the Registration Statements on Form F-10 (File No. 333-262342) and FormsS-8 (File No. 333-258940 and No. 333-262216) of Cardiol Therapeutics Inc. of our report dated March 28, 2023, relating to the consolidated financial statements which appear in this Annual Report on Form 20-F.

/s/ BDO Canada s.r.l./S.E.N.C.R.L./LLP

Montreal, Canada

March 28, 2023