X0306 4 2016-01-22 0 0001509190 ARATANA THERAPEUTICS, INC. PETX 0001578908 HEINEN ERNST C/O ARATANA THERAPEUTICS, INC. 11400 TOMAHAWK CREEK PARKWAY, SUITE 340 LEAWOOD KS 66211 0 1 0 0 Chief Development Officer Common Stock 2016-01-22 4 A 0 43000 0.00 A 140494 D Stock Option (Right to Buy) 3.14 2016-01-22 4 A 0 70000 0.00 A 2026-01-21 Common Stock 70000 70000 D Vests as to 25% of the total number of shares (rounded down to the nearest whole share) on January 29, 2017 and as to an additional 1/48th of the total number of shares (rounded down to the nearest whole share) on the same day of each of the 36 successive calendar months thereafter, such that the stock option shall be vested as to all shares on January 29, 2020, subject to continued service with the Issuer through the applicable vesting dates. /s/ John C. Ayres as Attorney-in-Fact for Ernst Heinen 2016-01-26