UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 Amendment No.: 2 Name of Issuer: IDEXX LABORATORIES INC Title of Class of Securities: Common CUSIP Number: 45168D104 (Date of Event Which Requires Filing of this Statement) December 31, 2005 Check the appropriate box to designate the rule pursuant to which this Schedule is filed: /X/ Rule 13d-l(b) / / Rule 13d-l(c) / / Rule 13d-l(d) *The remainder of this cover page shall be filled out for a reporting person's initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter the disclosures provided in a prior cover page. The information required in the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes). CUSIP Number: 45168D104 1. Name of Reporting Person S.S. or I.R.S. Identification No. of Above Person Ruane, Cunniff & Goldfarb Inc. 13-2628641 2. Check the Appropriate Box if a Member of a Group a. / / b. / / 3. SEC Use Only 4. Citizenship or Place of Organization Delaware Number of Shares Beneficially Owned by Each Reporting Person With: 5. Sole Voting Power: 2,575,980 6. Shared Voting Power: NONE 7. Sole Dispositive Power: 5,033,336 8. Shared Dispositive Power: NONE 9. Aggregate Amount Beneficially Owned by Each Reporting Person 5,033,336 10. Check Box if the Aggregate Amount in Row (9) Excludes Certain Shares / / 11. Percent of Class Represented by Amount in Row (9) 15.71% 12. Type of Reporting Person IA -2- Item 1(a) Name of Issuer: IDEXX LABORATORIES INC (b) Address of Issuer's Principal Executive Offices: One Idexx Drive, Westbrrok, ME 04092-2041 Item 2(a) - (c). Name, Principal Business Address, and Citizenship of Persons Filing: Ruane, Cunniff & Goldfarb Inc. 767 Fifth Avenue, New York, NY 10153-4798 Corp. organized under the laws of the State of Delaware (d) Title of Class of Securities: Common (e) CUSIP Number: 45168D104 Item 3. This statement is filed pursuant to Rule 13d-1(b)(1). / / Broker or Dealer registered under Section 15 of the Act. /x/ Investment Adviser registered under Section 203 of the Investment Advisers Act of 1940. Item 4. Ownership. (a) Amount Beneficially Owned: 5,033,336 (b) Percent of Class: 15.71% (c) (i) shares with sole power to vote or direct the vote: 2,575,980 (ii) shared power to vote or direct the vote: NONE (iii) shares with sole power to dispose or to direct the disposition of: 5,033,336 (iv) shares with shared power to dispose or direct the disposition of: NONE Item 5. Ownership of Five Percent or Less of a Class. If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than 5 percent of the class of securities, check the following / /. Item 6. Ownership of More than Five Percent on Behalf of Another Person. N/A -3- Item 7. Identification and Classification of the Subsidiary Which Acquired the Security Being Reported by the Parent Holding Company. N/A Item 8. Identification and Classification of Members of the Group. N/A Item 9. Notice of Dissolution of the Group. N/A Item 10. By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired in the ordinary course of business and were not acquired for the purpose and do not have the effect of changing or influencing the control of the issuer of such securities and were not acquired in connection with or as a participant in any transaction having such purpose or effect. After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct. By: /s/ Joseph Quinones, Jr. February 14, 2006 _________________________ _________________ Title: Vice-President Date