Exhibit 3.1

RESTATED CERTIFICATE OF INCORPORATION

OF

ARATANA THERAPEUTICS, INC.

I.

The name of this corporation is Aratana Therapeutics, Inc. (the “Corporation”).

II.

The address of the registered office of the Corporation in the State of Delaware is 251 Little Falls Drive, in the City of Wilmington, County of New Castle, Delaware 19808. The name of its registered agent at such address is Corporation Service Company.

III.

The purpose of this Corporation is to engage in any lawful act or activity for which a corporation may be organized under the Delaware General Corporation Law (“DGCL”).

IV.

This Corporation is authorized to issue Common Stock.  The total number of shares that the Corporation is authorized to issue is One Thousand (1,000) shares of Common Stock, each having a par value of $0.001.

V.

The management of the business and the conduct of the affairs of the Corporation shall be vested in its board of directors (the “Board of Directors”).  The number of directors that shall constitute the whole Board of Directors shall be fixed by the Board of Directors in the manner provided in the bylaws of the Corporation.

VI.

The Board of Directors may from time to time adopt, amend, alter, supplement, rescind or repeal any or all of the bylaws of the Corporation without any action on the part of the stockholders; provided, however, that the stockholders may adopt, amend or repeal any bylaw adopted by the Board of Directors, and no amendment or supplement to the bylaws adopted by the Board of Directors shall vary or conflict with any amendment or supplement adopted by the stockholders.

VII.

The Corporation reserves the right to amend, alter, change or repeal any provision contained in this Certificate of Incorporation, in the manner now or hereafter prescribed by statute, and all rights conferred upon the stockholders herein are granted subject to this reservation.

VIII.

Except to the extent that the DGCL prohibits the elimination or limitation of liability of directors for breaches of fiduciary duty, no director of the Corporation shall be personally liable to the Corporation or its stockholders for monetary damages for any breach of fiduciary duty as a director, notwithstanding any provision of law imposing such liability. No amendment to or repeal of this provision shall apply to or have any effect on the liability or alleged liability of any director of the Corporation for or with respect to any acts or omissions of such director occurring prior to such amendment or repeal. If the DGCL is amended to permit further elimination or limitation of the personal liability of directors, then the liability of a director of the Corporation shall be eliminated or limited to the fullest extent permitted by the DGCL as so amended.

IX.

Unless the Corporation consents in writing to the selection of an alternative forum, the Court of Chancery of the State of Delaware shall, to the fullest extent permitted by law, be the sole and exclusive forum for (a) any derivative action or proceeding brought on behalf of the Corporation, (b) any action asserting a claim of breach of fiduciary duty owed by, or other wrongdoing by, any director, officer, employee or agent of the Corporation to the Corporation or the Corporation’s stockholders, creditors or other constituents, (c) any action asserting a claim arising pursuant to any provision of the DGCL or this Certificate of Incorporation or the Bylaws of the Corporation, (d) any action to interpret, apply, enforce or determine the validity of this Certificate of Incorporation or the Bylaws of the Corporation or (e) any action asserting a claim governed by the internal affairs doctrine, in each case subject to said Court of Chancery having personal jurisdiction over the indispensable parties named as defendants therein; provided that, if and only if the Court of Chancery of the State of Delaware dismisses any such action for lack of subject matter jurisdiction, such action may be brought in another state or federal court sitting in the State of Delaware. To the fullest extent permitted by applicable law, any person or entity purchasing or otherwise acquiring any interest in shares of capital stock of the Corporation shall be deemed to have notice of and consented to the provisions of this Article IX. If any provision or provisions of this Article IX shall be held to be invalid, illegal or unenforceable as applied to any person or entity or circumstance for any reason whatsoever, then, to the fullest extent permitted by law, the validity, legality and enforceability of such provisions in any other circumstance and of the remaining provisions of this Article IX (including, without limitation, each portion of any sentence of this Article IX containing any such provision held to be invalid, illegal or unenforceable that is not itself held to be invalid, illegal or unenforceable) and the application of such provision to other persons or entities and circumstances shall not in any way be affected or impaired thereby.