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Filed pursuant to Rule 424(b)(3)
Registration No. 333-231811

ARATANA THERAPEUTICS, INC.
11400 Tomahawk Creek Parkway, Suite 340,
Leawood, KS 66211

June 17, 2019

PROPOSED MERGER—YOUR VOTE IS VERY IMPORTANT

To the Stockholders of Aratana Therapeutics, Inc.:

           You are cordially invited to attend a special meeting of stockholders (the "Aratana special meeting") of Aratana Therapeutics, Inc., a Delaware corporation ("Aratana"), to be held on July 16, 2019, at 9:00 a.m., Pacific Time, at the offices of Latham & Watkins LLP, Aratana's outside counsel, located at 12670 High Bluff Dr, San Diego, CA 92130.

           At the Aratana special meeting, you will be asked to consider and vote on a proposal to adopt the Agreement and Plan of Merger (as it may be amended from time to time, the "merger agreement"), dated April 26, 2019, by and among Elanco Animal Health Incorporated, an Indiana corporation ("Elanco"), Elanco Athens Inc., a Delaware corporation and a direct wholly owned subsidiary of Elanco ("Acquisition Sub"), and Aratana. Upon satisfaction or waiver of the conditions to the closing set forth in the merger agreement, Acquisition Sub will, at the closing, merge with and into Aratana (the "merger"), and Aratana will become a wholly owned subsidiary of Elanco. At the Aratana special meeting, you will also be asked to consider and vote on a non-binding, advisory proposal to approve compensation that will or may become payable to Aratana's named executive officers in connection with the merger and a proposal for the adjournment of the Aratana special meeting, if necessary or appropriate, in order to solicit additional votes to approve the adoption of the merger agreement.

           If the merger is completed, you will be entitled to receive (A) 0.1481 validly issued, fully paid and non-assessable shares of Elanco common stock, no par value per share, plus the right to receive cash in lieu of any fractional shares of Elanco common stock, and (B) one contingent value right representing the right to receive $0.25 in cash if the milestone is achieved, as set forth in the Contingent Value Rights Agreement (as described in the enclosed proxy statement/prospectus in the section titled "The Contingent Value Rights Agreement" beginning on page 121) for each share of Aratana common stock, par value $0.001 per share ("Aratana common stock"), you own immediately prior to the effective time of the merger (other than certain excluded shares as described in the merger agreement). On April 25, 2019, the last trading day before the public announcement of the signing of the merger agreement, the closing sale price per share of Elanco common stock on the New York Stock Exchange (the "NYSE") was $32.39. Based on the closing price per share of Elanco common stock on the NYSE on June 14, 2019 of $31.95, and based on the exchange ratio used in the merger, the stock consideration represented $4.73 in market value for each share of Aratana common stock. Based on the number of shares of Elanco common stock and Aratana common stock outstanding on June 13, 2019, upon completion of the merger, it is estimated that continuing Elanco shareholders will own approximately 98% of the issued and outstanding common stock of Elanco, and former Aratana stockholders will own approximately 2% of the issued and outstanding common stock of Elanco.

           The Board of Directors of Aratana (the "Aratana board"), after considering the factors more fully described in the enclosed proxy statement/prospectus, has unanimously (1) determined that the merger agreement and the transactions contemplated thereby are advisable and in the best interests of Aratana and its stockholders; and (2) approved and adopted the merger agreement. The Aratana board recommends that you vote (1) "FOR" the adoption of the merger agreement; (2) "FOR" the adjournment of the Aratana special meeting, if necessary or appropriate, in order to solicit additional votes to approve the adoption of the merger agreement; and (3) "FOR" the non-binding, advisory vote on the compensation that will or may become payable to Aratana's named executive officers in connection with the merger.

           The enclosed proxy statement/prospectus provides detailed information about the Aratana special meeting, the merger agreement and the merger. A copy of the merger agreement is attached as Appendix A to the proxy statement/prospectus. The proxy statement/prospectus also describes the actions and determinations of the Aratana board in connection with its evaluation of the merger agreement and the merger. We encourage you to read the proxy statement/prospectus and its appendices, including all documents incorporated by reference into the enclosed proxy statement/prospectus, carefully and in their entirety, as they contain important information.

           Whether or not you plan to attend the Aratana special meeting in person, please sign, date and return, as promptly as possible, the enclosed proxy card in the accompanying prepaid reply envelope or grant your proxy electronically over the Internet or by telephone. If you attend the Aratana special meeting and vote in person by ballot, your vote will revoke any proxy that you have previously submitted.

           If you hold your shares in "street name," you should instruct your bank, broker or other nominee how to vote your shares in accordance with the voting instruction form that you will receive from your bank, broker or other nominee. Your bank, broker or other nominee cannot vote on any of the proposals, including the proposal to adopt the merger agreement, without your instructions.

           Aratana common stock is listed on the Nasdaq Global Market ("Nasdaq") under the symbol "PETX". Elanco common stock is listed on the NYSE under the symbol "ELAN". We urge you to obtain current market quotations for the shares of common stock of Aratana and Elanco.

           Your vote is very important, regardless of the number of shares that you own. We cannot complete the merger unless the proposal to adopt the merger agreement is approved by the affirmative vote of the holders of a majority of the shares of Aratana common stock outstanding as of the record date entitled to vote on the proposal. Information about the Aratana special meeting, the merger and the other business to be considered by Aratana stockholders at the Aratana special meeting is contained in the enclosed proxy statement/prospectus.

           We urge you to read this proxy statement/prospectus carefully. You should also carefully consider the risks that are described in the section titled "Risk Factors" beginning on page 26.

           If you have any questions or need assistance voting your shares, please contact Aratana's proxy solicitor:

MacKenzie Partners, Inc.

1407 Broadway, 27^th Floor
New York, New York 10018

+1-800-322-2885
proxy@mackenziepartners.com

On behalf of the Aratana board, I thank you for your support and appreciate your consideration of this matter.

		Sincerely,
		Craig A. Tooman
		President and Chief Executive Officer Aratana Therapeutics, Inc.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities, or passed upon the adequacy or accuracy of this proxy statement/prospectus. Any representation to the contrary is a criminal offense.

           This proxy statement/prospectus is dated June 17, 2019 and, together with the enclosed form of proxy card, is first being mailed to stockholders on or about June 17, 2019.

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ARATANA THERAPEUTICS, INC.
11400 Tomahawk Creek Parkway, Suite 340,
Leawood, KS 66211

NOTICE OF SPECIAL MEETING OF STOCKHOLDERS
TO BE HELD ON JULY 16, 2019

        Notice is hereby given that a special meeting of stockholders (the "Aratana special meeting") of Aratana Therapeutics, Inc., a Delaware corporation ("Aratana"), will be held on July 16, 2019, at 9:00 a.m., Pacific Time, at the offices of Latham & Watkins LLP, Aratana's outside counsel, located at 12670 High Bluff Dr, San Diego, CA 92130, at which you will be asked to consider and vote upon the following proposals:

1.

Merger proposal: To adopt the Agreement and Plan of Merger (as it may be amended from time to time, the "merger agreement"), dated April 26, 2019, by and among Elanco Animal Health Incorporated, an Indiana corporation ("Elanco"), Elanco Athens Inc., a Delaware corporation and a direct wholly owned subsidiary of Elanco ("Acquisition Sub"), and Aratana, pursuant to which, upon the satisfaction or waiver of the conditions to the closing set forth in the merger agreement, Acquisition Sub will merge with and into Aratana (the "merger"), with Aratana surviving as a wholly owned subsidiary of Elanco;



2.

Adjournment proposal: To adjourn the Aratana special meeting, if necessary or appropriate, in order to solicit additional proxies if there are insufficient votes to adopt the merger agreement at the time of the Aratana special meeting; and



3.

Non-binding, advisory merger-related compensation proposal: To approve, by non-binding, advisory vote, compensation that will or may become payable to Aratana's named executive officers in connection with the merger.

        Aratana's Board of Directors (the "Aratana board") has set June 14, 2019 as the record date for the Aratana special meeting. Only stockholders of record as of the close of business on the record date are entitled to notice of the Aratana special meeting and to vote at the Aratana special meeting or any adjournment, postponement or other delay thereof.

        The Aratana board unanimously recommends that you vote (1) "FOR" the merger proposal; (2) "FOR" the adjournment proposal; and (3) "FOR" the non-binding, advisory merger-related compensation proposal.

        Whether or not you plan to attend the Aratana special meeting in person, please sign, date and return, as promptly as possible, the enclosed proxy card in the accompanying prepaid reply envelope or grant your proxy electronically over the Internet or by telephone. If you attend the Aratana special meeting and vote in person by ballot, your vote will revoke any proxy that you have previously submitted. If you hold your shares in "street name," you should instruct your bank, broker or other nominee how to vote your shares in accordance with the voting instruction form that you will receive from your bank, broker or other nominee. Your bank, broker or other nominee cannot vote on any of the proposals, including the proposal to adopt the merger agreement, without your instructions.

		By the Order of the Aratana Board,
		John C. Ayres
		Secretary
		Aratana Therapeutics, Inc. June 17, 2019

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YOUR VOTE IS IMPORTANT

        If you hold your shares in "street name," you should instruct your bank, broker or other nominee how to vote your shares in accordance with the voting instruction form that you will receive from your bank, broker or other nominee. Your bank, broker or other nominee cannot vote on any of the proposals, including the proposal to adopt the merger agreement, without your instructions.

        If you are a stockholder of record, voting in person by ballot at the Aratana special meeting will revoke any proxy that you previously submitted. If you hold your shares through a bank, broker or other nominee, you must obtain a "legal proxy" in order to vote in person at the Aratana special meeting.

        If you fail to either (1) return your proxy card, (2) grant your proxy electronically over the Internet or by telephone or (3) vote at the Aratana special meeting in person, your shares will not be counted for purposes of determining whether a quorum is present at the Aratana special meeting and, if a quorum is present, will have the same effect as a vote "AGAINST" the proposal to adopt the merger agreement. Abstentions will have the same effect as a vote "AGAINST" the proposal to adopt the merger agreement.

        We encourage you to read the accompanying proxy statement/prospectus and its appendices, including all documents incorporated by reference into the accompanying proxy statement/prospectus, carefully and in their entirety. If you have any questions concerning the merger, the Aratana special meeting or the accompanying proxy statement/prospectus, would like additional copies of the accompanying proxy statement/prospectus or need help voting your shares of Aratana common stock, please contact Aratana's proxy solicitor:

MacKenzie Partners, Inc.

1407 Broadway, 27^th Floor
New York, New York 10018

+1-800-322-2885
proxy@mackenziepartners.com

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ABOUT THIS PROXY STATEMENT/PROSPECTUS

        This proxy statement/prospectus, which forms part of a registration statement on Form S-4 filed with the Securities and Exchange Commission (the "SEC") by Elanco Animal Health Incorporated ("Elanco") (File No. 333-231811), constitutes a prospectus of Elanco under Section 5 of the Securities Act of 1933, as amended (the "Securities Act"), with respect to the shares of common stock, no par value per share, of Elanco, to be issued to Aratana stockholders pursuant to the Agreement and Plan of Merger (as it may be amended from time to time, the "merger agreement"), dated as of April 26, 2019, by and among Elanco, Elanco Athens Inc. ("Acquisition Sub"), and Aratana Therapeutics, Inc. ("Aratana"). This document also constitutes a notice of meeting and a proxy statement of Aratana under Section 14(a) of the Securities Exchange Act of 1934, as amended (the "Exchange Act"), with respect to the special meeting of Aratana stockholders (the "Aratana special meeting"), at which Aratana stockholders will be asked to consider and vote on, among other proposals, a proposal to adopt the merger agreement.

        You should rely only on the information contained in or incorporated by reference into this proxy statement/prospectus. No one has been authorized to provide you with information that is different from that contained in or incorporated by reference into this proxy statement/prospectus. This proxy statement/prospectus is dated June 17, 2019, and you should not assume that the information contained in this proxy statement/prospectus is accurate as of any date other than the date hereof or any earlier date provided herein. Further, you should not assume that the information incorporated by reference into this proxy statement/prospectus is accurate as of any date other than the date of the incorporated document or any earlier date provided therein. Neither the mailing of this proxy statement/prospectus to Aratana stockholders nor the issuance by Elanco of shares of its common stock pursuant to the merger agreement will create any implication to the contrary.

        This proxy statement/prospectus does not constitute an offer to sell, or a solicitation of an offer to buy, any securities, or the solicitation of a proxy, in any jurisdiction in which or from any person to whom it is unlawful to make any such offer or solicitation in such jurisdiction. Information contained in this proxy statement/prospectus regarding Elanco has been provided by Elanco and information contained in or incorporated by reference into this proxy statement/prospectus regarding Aratana has been provided by Aratana.

        This proxy statement/prospectus incorporates by reference important business and financial information about Elanco and Aratana from other documents that are not included in or delivered with this proxy statement/prospectus. This information is available to you without charge upon your request. You can obtain the documents incorporated by reference into this proxy statement/prospectus by requesting them in writing or by telephone from the appropriate company at the following addresses and telephone numbers:

        In order to ensure timely delivery of these documents, you should make your request by July 9, 2019, to receive them before the Aratana special meeting.

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        If you have any questions about the Aratana special meeting or need additional assistance in voting your shares, please contact Aratana's proxy solicitor:

MacKenzie Partners, Inc.
1407 Broadway, 27^th Floor
New York, New York 10018
+1-800-322-2885
proxy@mackenziepartners.com

        You can also obtain documents incorporated by reference into this proxy statement/prospectus through the website of the SEC at www.sec.gov. For a more detailed description of the information incorporated by reference into this proxy statement/prospectus and how you may obtain it, see "Where You Can Find More Information" beginning on page 259.

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QUESTIONS AND ANSWERS ABOUT THE ARATANA SPECIAL MEETING AND THE MERGER

        The following questions and answers briefly address some commonly asked questions that you, as a stockholder of Aratana, may have in connection with the merger, the merger agreement and the Aratana special meeting. Elanco and Aratana urge you to read carefully this entire proxy statement/prospectus, including the appendices and the documents incorporated by reference into this proxy statement/prospectus, because the information in this section does not provide all the information that might be important to you. You may obtain the information incorporated by reference in this proxy statement/prospectus without charge by following the instructions under the section titled "Where You Can Find More Information" beginning on page 259.

Q:

Why is Aratana proposing the merger?

A:

The Aratana board believes that the proposed merger will provide a number of significant potential strategic benefits and opportunities that will be in the best interests of Aratana stockholders. To review the reasons for the proposed merger in greater detail, see "The Merger—Aratana Board Recommendation and Its Reasons for the Merger" beginning on page 71.

Q:

Why am I receiving this proxy statement/prospectus?

A:

Aratana and Elanco have agreed to a merger, pursuant to which (subject to certain conditions described in the merger agreement) Acquisition Sub will merge with and into Aratana, with Aratana surviving the merger as a wholly owned subsidiary of Elanco. Aratana is sending this proxy statement/prospectus to its stockholders to help them decide how to vote their shares of Aratana common stock with respect to the merger and other matters to be considered at the Aratana special meeting. The merger cannot be completed unless Aratana stockholders adopt the merger agreement. Aratana is holding the Aratana special meeting to allow Aratana stockholders to vote on the proposal to adopt the merger and certain related proposals.

This proxy statement/prospectus contains important information about Elanco, Aratana, the Aratana special meeting, the merger agreement, and the merger. This document constitutes both a proxy statement of Aratana and a prospectus of Elanco. It is a proxy statement because the Aratana board is soliciting proxies from Aratana stockholders. It is a prospectus because Elanco will issue shares of Elanco common stock in exchange for outstanding shares of Aratana common stock in the merger.

You are receiving this proxy statement/prospectus because you have been identified as a stockholder of Aratana and may be entitled to vote at the upcoming Aratana special meeting. You should read this proxy statement/prospectus carefully.

Q:

What will holders of Aratana common stock receive in the merger?

A:

Upon completion of the merger, each Aratana stockholder as of the effective time of the merger will be entitled to receive, with regard to each share of Aratana common stock that is outstanding immediately prior to the effective time of the merger (excluding cancelled shares and any shares held by holders who have exercised their appraisal rights), (A) 0.1481 validly issued, fully paid and non-assessable shares of Elanco common stock, no par value per share ("Elanco common stock") (the "stock consideration"), plus the right to receive cash in lieu of any fractional shares of Elanco common stock, and (B) one contingent value right (a "CVR," and together with the stock consideration and the right to receive cash in lieu of any fractional shares of Elanco common stock, the "merger consideration") representing the right to receive $0.25 in cash if the milestone is achieved, as set forth in the Contingent Value Rights Agreement (the "CVR agreement").

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Q:

What are the CVRs?

A:

The CVRs are non-transferable contingent value rights that will be issued as part of the merger consideration. Each CVR will entitle its holder to receive $0.25 in cash if Aratana, Elanco or their respective affiliates achieve cumulative net sales of an animal health product that contains capromorelin as an active pharmaceutical ingredient equal to or exceeding (i) $25,000,000 during the period beginning on July 1, 2019 and ending on December 31, 2020, or (ii) $50,000,000 during the period beginning on July 1, 2019 and ending on December 31, 2021.

There can be no assurance that any payment will be made under the CVRs. The amounts to be received in connection with the CVRs, and the timing of any payments of any such amounts, are contingent upon the occurrence of certain events which may or may not occur, and which may be outside the control of Elanco or Aratana. There may be no cash consideration ultimately paid in respect of the CVRs. The CVRs will be non-transferable and, accordingly, will not be listed on any securities exchange.

See "The Contingent Value Rights Agreement" beginning on page 121. A form of the CVR agreement is attached as Appendix D to this proxy statement/prospectus. Aratana stockholders are encouraged to read the entire form of CVR agreement carefully because it is the principal document governing the CVRs.

Q:

What happens if the market price of shares of Elanco common stock or Aratana common stock changes before the effective time of the merger?

A:

No change will be made to the merger consideration if the market price of shares of Elanco common stock or Aratana common stock changes before the effective time of the merger. Accordingly, the value of the stock portion of the merger consideration to be received by Aratana stockholders in the merger will depend on the market price of shares of Elanco common stock at the effective time of the merger.

Q:

What am I being asked to vote on at the Aratana special meeting and why is this approval necessary?

A:

Aratana stockholders are being asked to vote on the following proposals:

•

Merger proposal:  To adopt the merger agreement, pursuant to which Acquisition Sub will merge with and into Aratana, with Aratana surviving as a wholly owned subsidiary of Elanco;

•

Adjournment proposal:  To adjourn the Aratana special meeting, if necessary or appropriate, in order to solicit additional proxies if there are insufficient votes to adopt the merger agreement at the time of the Aratana special meeting; and

•

Non-binding, advisory merger-related compensation proposal:  To approve, by non-binding, advisory vote, compensation that will or may become payable to Aratana's named executive officers in connection with the merger.

Approval of the merger proposal is required for completion of the merger. Approval of the adjournment proposal or the non-binding, advisory merger-related compensation proposal is not a condition to the obligations of Aratana or Elanco to complete the merger.

Q:

What vote is required to approve each of the proposals that will be presented at the Aratana special meeting?

A:

Merger proposal: The affirmative vote of holders of a majority of the shares of Aratana common stock outstanding as of June 14, 2019 (the "record date") entitled to vote on the merger proposal.

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An abstention, broker non-vote, or a failure to vote will have the same effect as a vote "AGAINST" this proposal.

Adjournment proposal: The affirmative vote of a majority in voting power of the votes cast at the Aratana special meeting, affirmatively or negatively, by the holders entitled to vote thereon. An abstention, broker non-vote, or a failure to vote will have no effect on the outcome of this proposal.

Non-binding, advisory merger-related compensation proposal: The affirmative vote of a majority in voting power of the votes cast at the Aratana special meeting, affirmatively or negatively, by the holders entitled to vote thereon. An abstention, broker non-vote, or a failure to vote will have no effect on the outcome of this proposal. The vote with respect to the non-binding, advisory merger-related compensation proposal is an advisory vote and will not be binding on Aratana. If the merger agreement is adopted by the stockholders and the merger is completed, the compensation that will or may become payable by Aratana to its named executive officers in connection with the merger may be paid to Aratana's named executive officers even if stockholders fail to approve the non-binding, advisory merger-related compensation proposal.

Q:

How many shares must be present to hold the Aratana special meeting?

A:

A quorum must be present at the Aratana special meeting for any business to be conducted. A quorum requires the presence, in person or by proxy, of Aratana stockholders who hold a majority of the voting power of Aratana common stock entitled to vote at the Aratana special meeting. Any shares that are the subject of abstentions will be treated as present for the purposes of determining whether a quorum exists at the Aratana special meeting.

Shares of Aratana common stock held in "street name" through a bank, broker or other nominee with respect to which the beneficial owner fails to give voting instructions to the bank, broker or other nominee will not be deemed present for the purpose of determining whether a quorum exists at the Aratana special meeting.

Q:

As a stockholder of Aratana, how does the Aratana board recommend that I vote?

A:

The Aratana board unanimously recommends that Aratana's stockholders vote "FOR" the merger proposal, "FOR" the non-binding, advisory merger-related compensation proposal and "FOR" the adjournment proposal.

Q:

What risks should I consider before I vote?

A:

You should consider all the information contained in or incorporated by reference into this proxy statement/prospectus in deciding how to vote for the proposals presented herein. In particular, you should consider the factors described under "Risk Factors" beginning on page 26.

Q:

How do I vote?

A:

Aratana stockholders of record as of the record date may vote by proxy before the Aratana special meeting in one of the following ways:

•

By Telephone:  By dialing the toll-free number specified on the proxy card and following the instructions on the proxy card;

•

Via the Internet:  By accessing the website specified on the proxy card and following the instructions on the proxy card; or

•

By Mail:  By completing and returning the proxy card in the enclosed envelope. The envelope requires no additional postage if mailed in the United States.

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Aratana stockholders may also cast their votes in person at the Aratana special meeting.

If shares are held in street name through a bank or broker, Aratana stockholders will receive instructions on how to vote from the bank or broker. Aratana stockholders must follow their instructions in order for their shares to be voted. Telephone and Internet voting also may be offered to stockholders owning shares through certain banks and brokers. If Aratana stockholders hold shares that are not registered in their own name and they would like to vote such shares in person at the Aratana special meeting, Aratana stockholders should contact their bank or broker to obtain a legal proxy and bring it to the Aratana special meeting in order to vote.

Q:

What is the difference between being a "record holder" and holding shares in "street name"?

A:

A record holder holds shares in his or her name. Shares held in "street name" means shares that are held in the name of a bank or broker on a person's behalf.

Q:

If my shares are held in "street name" by a broker, bank or other nominee, will my broker, bank or other nominee vote my shares for me?

A:

Not unless you instruct them to do so. If your shares are held in "street name" in a stock brokerage account or by a bank or other nominee, you must provide the record holder of your shares with instructions on how to vote your shares. Please follow the voting instructions provided by your broker, bank or other nominee.

Please note that you may not vote shares held in street name by returning a proxy card directly to Aratana or by voting in person at the Aratana special meeting unless you provide a "legal proxy", which you must obtain from your broker, bank or other nominee.

Brokers, banks, or other nominees who hold shares of Aratana common stock in "street name" have the authority to vote in their discretion on "routine" proposals when they have not received instructions on how to vote from the beneficial owner. However, brokers, banks and other nominees are not allowed to exercise their voting discretion on matters that are "non-routine" without specific instructions on how to vote from the beneficial owner. None of the proposals, including the merger proposal, that will be voted on at the Aratana special meeting, is "routine." Therefore, brokers, banks and other nominees do not have discretionary authority to vote on any of the proposals.

A broker non-vote would occur if (i) the holder of a share of Aratana common stock held by a broker, bank or other nominee is present, in person or represented by proxy, at the Aratana special meeting, (ii) the beneficial owner of that share has not instructed his, her or its broker, bank or other nominee on how to vote on a particular proposal and (iii) the broker, bank or other nominee does not have discretionary voting power on such proposal. Since brokers, banks and other nominees do not have discretionary voting authority with respect to any of the proposals that will be voted on at the Aratana special meeting, if a beneficial owner of shares of Aratana common stock held in "street name" does not give voting instructions to the broker, bank or other nominee, then those shares will not be present in person or represented by proxy at the Aratana special meeting. As a result, we do not expect there to be any broker non-votes at the Aratana special meeting.

Q:

What if I do not vote or abstain?

A:

For purposes of the Aratana special meeting, an abstention occurs when a stockholder who has not submitted a proxy attends the Aratana special meeting in person and does not vote, or a stockholder returns a proxy with an "abstain" vote.

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Because approval of the merger proposal requires the affirmative vote of holders of a majority of the shares of Aratana common stock outstanding as of the record date entitled to vote on the merger proposal, if you fail to vote or fail to instruct your broker, bank or other nominee how to vote on the merger proposal or you mark your proxy "abstain" with regard to the merger proposal, that will have the same effect as a vote "AGAINST" the merger proposal. Failure to vote, or voting "abstain," will have no effect on the outcome of the vote on the adjournment proposal or the non-binding, advisory merger-related compensation proposal.

Q:

What will happen if I return my proxy without indicating how to vote?

A:

If you sign and return your proxy without indicating how to vote on any particular proposal, the Aratana common stock represented by your proxy will be voted as recommended by the Aratana board with respect to that proposal. That means that a signed proxy that does not indicate how to vote will be voted "FOR" all three proposals.

Q:

What happens if I sell my shares of Aratana common stock after the record date but before the Aratana special meeting?

A:

The record date for the Aratana special meeting is earlier than the date of the Aratana special meeting and earlier than the date that the merger is expected to be completed. If you sell or otherwise transfer your shares of Aratana common stock after the record date but before the date of the Aratana special meeting, you will retain your right to vote at the Aratana special meeting. However, you will not have the right to receive the merger consideration to be received by Aratana stockholders in the merger or exercise appraisal rights. In order to receive the merger consideration or exercise appraisal rights, you must hold your shares of Aratana common stock through completion of the merger.

Q:

What does it mean if I receive more than one proxy card or vote instruction card?

A:

Your receipt of more than one proxy card or vote instruction card may mean that you have multiple accounts with Aratana's transfer agent or with a brokerage firm, bank or other nominee. If voting by proxy by mail, you will need to sign and return all proxy cards or vote instruction cards to ensure that all of your shares of Aratana common stock are voted. Each proxy card or vote instruction card represents a distinct number of shares of Aratana common stock and it is the only means by which those particular shares of Aratana common stock may be voted by proxy.

Q:

May I change my vote after I have submitted a proxy?

A:

Yes.

Registered Aratana stockholders may revoke their proxy and change their vote:

•

by submitting a duly executed proxy bearing a later date;



•

by granting a subsequent proxy through the Internet or telephone;



•

by giving written notice of revocation to the Secretary of Aratana prior to or at the Aratana special meeting; or



•

by voting in person at the Aratana special meeting.

The most recent proxy card or telephone or Internet proxy is the one that is counted. Attendance at the Aratana special meeting by itself will not revoke a proxy unless an Aratana stockholder gives written notice of revocation to the Secretary before their proxy is voted or an Aratana stockholder votes in person at the Aratana special meeting.

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Q:

Who will count the votes?

A:

A representative of Broadridge Financial Solutions, Inc., Aratana's inspector of election, will tabulate and certify the votes.

Q:

Do any of Aratana's directors or executive officers have interests in the merger that are in addition to or may differ from those of Aratana's stockholders?

A:

Yes. In considering whether to approve the proposals at the Aratana special meeting, Aratana stockholders should recognize that certain Aratana directors and executive officers have interests in the merger that differ from, or that are in addition to, your interests as Aratana stockholders. These interests include, among others, eligibility to receive accelerated vesting of equity awards, transaction bonuses and eligibility to receive certain severance benefits that result from the merger. These interests, among others, may influence the Aratana directors and executive officers to support or approve the merger proposal. See "The Merger—Interests of Aratana Directors and Officers in the Merger" beginning on page 89.

Q:

Will my rights as a stockholder of Aratana change as a result of the merger?

A:

Yes. Aratana stockholders will receive the merger consideration, including Elanco common stock and CVRs, if the merger is completed. Aratana stockholders will have different rights as a holder of Elanco common stock following the closing of the merger due to the differences between the governing documents of and governing law applicable to Elanco and Aratana. See "Comparison of Rights of Holders of Elanco Common Stock and Aratana Common Stock" beginning on page 241. See "The Contingent Value Rights Agreement" beginning on page 121 for a summary of the rights of holders of CVRs.

Q:

Where will my shares of Elanco common stock be traded?

A:

Shares of Elanco common stock currently trade on the NYSE under the symbol "ELAN". Elanco will apply to have the new shares of Elanco common stock issued as consideration in the merger listed on the NYSE prior to the effective time of the merger, subject to official notice of issuance.

Q:

What are the United States federal income tax consequences of the merger to me?

A:

Elanco and Aratana intend that, for U.S. federal income tax purposes, the merger will qualify as a "reorganization" within the meaning of Section 368(a) of the Internal Revenue Code of 1986, as amended (the "Code"). The merger for this purpose includes the first merger and the second merger, if it occurs, as part of one integrated plan of reorganization for U.S. federal income tax purposes. The obligations of each of Elanco and Aratana to consummate the merger are conditioned upon the receipt by each of them of an opinion dated as of the closing of the merger, to the effect that that the merger will qualify for U.S. federal income tax purposes as a "reorganization" within the meaning of Section 368(a) of the Code. Elanco will receive an opinion from its counsel, Bryan Cave Leighton Paisner LLP. Aratana will receive an opinion from its counsel, Latham & Watkins LLP. On the basis of such opinions, a U.S. Holder generally will not recognize any gain or loss upon the receipt of shares of Elanco common stock in the merger, other than gain recognized with respect to the receipt of cash in lieu of fractional shares and CVRs. For a more complete summary of the material U.S. federal income tax consequences of the merger to holders of Aratana common stock, see "Material U.S. Federal Income Tax Consequences" beginning on page 250.

Stockholders should consult with their tax advisors with regard to the tax consequences of the merger to them in light of their own particular circumstances.

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Q:

Are there any conditions to the closing of the merger that must be satisfied for the merger to be completed?

A:

Yes. In addition to the approval of the stockholders of Aratana described herein, there are a number of conditions that must be satisfied or waived for the merger to be completed. See "The Merger Agreement—Conditions to Completion of the Merger" beginning on page 116.

Q:

When is the merger expected to close?

A:

Elanco and Aratana are working to close the merger as promptly as practicable and expect it to be completed in mid-year 2019 timeframe. In addition to obtaining the approval of Aratana stockholders, the merger is subject to certain other closing conditions, as discussed further in "The Merger Agreement—Conditions to Completion of the Merger" beginning on page 116. The closing of the merger will take place no later than the second business day following the date on which the last of the closing conditions of the merger have been satisfied or waived.

Q:

Will fractional shares be issued?

A:

No. If the aggregate number of shares of Elanco common stock that you are otherwise entitled to receive as part of the merger consideration includes a fraction of a share of Elanco common stock, you will receive cash in an amount equal to and in lieu of the fractional share. See "The Merger Agreement—Merger Consideration" beginning on page 102.

Q:

Will Elanco shareholders receive any shares or cash in the merger?

A:

No. Elanco shareholders will continue to own the same number of shares of Elanco common stock that they owned before the effective time of the merger and will not receive any merger consideration, except to the extent they also own shares of Aratana common stock.

Q:

What happens if the merger is not completed?

A:

If the merger proposal is not approved by the holders of a majority of the shares of Aratana common stock outstanding as of the record date entitled to vote on the merger proposal, or if the merger is not completed for any other reason, holders of Aratana common stock would not receive any consideration from Elanco for their shares of Aratana common stock. Instead, Aratana would remain an independent public company, and Aratana common stock would continue to be registered under the Exchange Act and listed and traded on Nasdaq. If the merger agreement is terminated under specified conditions, including with respect to Aratana's termination of the merger agreement in connection with a superior proposal, as defined in the section titled "The Merger Agreement—No Solicitation" beginning on page 110, Aratana may be required to pay Elanco a termination fee of $7.0 million (the "termination fee"). Following payment of the termination fee, Aratana would not have any further liability to Elanco in respect of the merger agreement (other than liability for any willful breach or fraud). See "The Merger Agreement—Fees and Expenses; Termination Fee" beginning on page 119.

Q:

Am I entitled to exercise appraisal rights instead of receiving the per share merger consideration for my shares of Aratana common stock?

A:

Yes. See "The Merger—Appraisal Rights" beginning on page 95.

Q:

When and where is the Aratana special meeting?

A:

The Aratana special meeting will be held on July 16, 2019, at 9:00 a.m., Pacific Time, at the offices of Latham & Watkins LLP, Aratana's outside counsel, located at 12670 High Bluff Dr, San Diego,

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CA 92130. Subject to space availability, all Aratana stockholders as of the record date, or their duly appointed proxies, may attend the Aratana special meeting. Since seating is limited, admission to the Aratana special meeting will be on a first-come, first-served basis. Registration and seating will begin at 8:30 a.m., Pacific Time on the day of the Aratana special meeting.

Q:

What do I need to do now?

A:

After you have carefully read this proxy statement/prospectus, please respond by completing, signing and dating your proxy card and returning it in the enclosed pre-addressed postage-paid envelope or, if available, by submitting your proxy by one of the other methods specified in your proxy card as promptly as possible so that your shares of Aratana common stock will be represented and voted at the Aratana special meeting. Please refer to your vote instruction card forwarded by your broker or other nominee to see which voting options are available to you.

The method by which you submit a proxy will in no way limit your right to vote at the Aratana special meeting if you later decide to attend the meeting in person. Your vote as an Aratana stockholder is important. Accordingly, please sign and return the enclosed proxy card whether or not you plan to attend the Aratana special meeting in person.

However, if your shares of Aratana common stock are held in the name of a broker or other nominee, you must obtain a legal proxy, executed in your favor, from your broker or other nominee, to be able to vote in person at the Aratana special meeting.

Q:

Will a proxy solicitor be used?

A:

Yes. Aratana has engaged MacKenzie Partners, Inc. ("MacKenzie") to assist in the solicitation of proxies for the Aratana special meeting and Aratana estimates that it will pay MacKenzie a fee of approximately $15,000. Aratana has also agreed to reimburse MacKenzie for reasonable out-of-pocket expenses and disbursements incurred in connection with the proxy solicitation and to indemnify MacKenzie against certain losses, claims, damages, liabilities and expenses. In addition to mailing proxy solicitation material, Aratana's directors, officers and employees may also solicit proxies in person, by telephone or by any other electronic means of communication deemed appropriate. No additional compensation will be paid to Aratana's directors, officers or employees for such services.

Q:

Who should I contact if I have other questions about the merger agreement or the merger?

A:

If you have more questions about the merger agreement or the merger, you should contact Aratana's proxy solicitation agent, MacKenzie, toll-free at 1-800-322-2885, or via email at proxy@mackenziepartners.com. If your broker holds your shares, you should also call your broker for additional information.

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