X0306 4 2012-10-04 0 0001038133 HESKA CORP HSKA 0001471373 CMC Master Fund, L.P. C/O C.M. CAPITAL ADVISORS, LLC 525 UNIVERSITY AVENUE, SUITE 200 PALO ALTO CA 94301 0 0 1 0 0001471663 CMC Master Fund Partners, LLC C/O C.M. CAPITAL ADVISORS, LLC 525 UNIVERSITY AVENUE, SUITE 200 PALO ALTO CA 94301 0 0 1 0 Common Stock 2012-10-04 4 S 0 9600 9.5022 D 558443 I See Footnote Common Stock 2012-10-05 4 S 0 14462 9.5339 D 543981 I See Footnote Common Stock 2012-10-08 4 S 0 2452 9.50 D 541529 I See Footnote The reported price is based on a weighted average of multiple same-day transactions with prices ranging from $9.50 to $9.54 per share. The reporting persons undertake to provide upon request to the staff of the Securities and Exchange Commission, the Issuer or any security holder of the Issuer full information regarding the number of shares sold at each separate price. These shares are held directly by CMC Master Fund, L.P., and indirectly by CMC Master Fund Partners, LLC, as the general partner of CMC Master Fund, L.P. Each of the reporting persons disclaims beneficial ownership of such securities, except to the extent of its proportionate pecuniary interest therein. The reported price is based on a weighted average of multiple same-day transactions with prices ranging from $9.50 to $9.58 per share. The reporting persons undertake to provide upon request to the staff of the Securities and Exchange Commission, the Issuer or any security holder of the Issuer full information regarding the number of shares sold at each separate price. CMC Master Fund Partners, LLC, By: /s/ Fernando Sucre, Senior V.P., CFO 2012-10-09 CMC Master Fund, L.P., By: CMC Master Fund Partners, LLC, its General Partner, By: /s/ Fernando Sucre, Senior V.P., CFO 2012-10-09