EXHIBIT 10.41.1
                                                                 ---------------

                            ADDENDUM TO AGREEMENT  

The Agreement between Rhone Merieux, Inc. ("RMI") and Synbiotics ("Synbiotics")
dated January 1, 1992 (the "Agreement"), is amended as follows:

1.0  Effective immediately, Synbiotics shall have rights to market FeLV R,C,P
     (live) and CHL combination vaccine (see Section 1.2.1 of the Agreement) as
     provided by RMI in the United States, Canada and Mexico. Synbiotics shall
     not market thin vaccine directly to veterinarians or to or through other
     biological manufacturers. Synbiotics will not indicate to any third party
     that any of its products are of Rhone Merieux origin.

2.0  Effective 17 August 1995 as per letter agreement, RMI shall have rights to
     market Synbiotics' FeLV vaccine (monovalent) in Canada, either direct or
     through RMI distributors.  This marketing right shall be co-exclusive, with
     only Synbiotics retaining the right to appoint one distributor (but no more
     than one distributor) to market FeLV vaccine (monovalent) in Canada (direct
     or through subdistributors). The marketing rights granted to RMI in this
     Section 2 shall apply only to finished, final FeLV (monovalent) products
     manufactured by RMI from bulk FeLV supplied by Synbiotics. No royalty shall
     be due from RMI to Synbiotics on sales of FeLV vaccine (monovalent) in
     Canada.

3.0  The scheduled expiration date of the Agreement is amended to be December 
     31, 2004.

4.0  Section 2.2.1 of the Agreement shall be amended in its entirety to read as
     follows:

     2.2.1 "RMI's annual requirement of bulk, tested, completed FeLV Product
           ("FeLV"), at a purchase price of [*] per one dose equivalent (defined
           as 1.2 ml) through December 31, 1997 and at a purchase price of [*]
           from January 1, 1998 until the expiration or earlier termination of
           the Agreement.  Notwithstanding the foregoing, Synbiotics shall have
           the right to increase the prices set forth herein: (i) in the event
           that the United States Animal and Plant Health Inspection Service
           officially requires Synbiotics to upgrade its manufacturing
           facilities, but no such price increase may occur prior to 31 December
           1999 and if such increase is necessary, the price of FeLV shall not
           exceed [*]/one dose equivalent; or (ii) Synbiotics reasonably
           determines that a price increase shall be restricted to a case where
           the annual inflation rate at the end of a given calendar year exceeds
           ten (10%) percent according to the U.S. Producer Price Index.  The
           parties will agree to meet in such a case and mutually agree upon the
           future price of the FeLV; or (iii) Synbiotics reasonably determines
           that an improvement has resulted in an increase in value provided,
           however, the price of FeLV shall not exceed [*] per one dose
           equivalent."

5.0  Synbiotics shall pay a royalty to RMI on all net sales by Synbiotics of all
     Products containing RMI Components equal to [*] percent of net sales during
     the remainder of this Agreement.

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[*]  Certain confidential portions of this Exhibit were omitted by means of
     blackout of the text (the "Mark").  This Exhibit has been filed
     separately with the Secretary of the Commission without the Mark
     pursuant to the Company's Application Requesting Confidential Treatment
     under Rule 24b-2 under the Securities Exchange Act of 1934, as amended.

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6.0  Section 3.3.2 of the Agreement shall be amended in its entirety to read as
     follows:

     3.3.2 RMI shall pay a royalty to Synbiotics on Synbiotics origin FeLV net
           sales by RMI as follows:
 
 
     a.    FeLV Monovalent (USA Only)             Royalty Rates
           --------------------------             -------------
                                               
           1 Sept. 95 - 31 Oct. 95                     [*]
           1 Nov. 95 - 31 Oct. 96                      [*]
           1 Nov. 96 - 31 Oct. 97                      [*]
           1 Nov. 97 - 31 Dec. 99                      [*]
           1 Jan. 2000 - 31 Dec. 2004                  [*]


 
 
     b.    FeLV Combinations (USA/CANADA/MEXICO)  Royalty Rates
           -------------------------------------  -------------
                                               
           1 Sept. 95 - 31 Oct. 95                     [*]
           1 Nov. 95 - 31 Oct. 96                      [*]
           1 Nov. 96 - 31 Oct. 97                      [*]
           1 Nov. 97 - 31 Dec. 99                      [*]
           1 Jan. 2000 - 31 Dec. 2004                  [*]


7.0  All capitalized terms shall have the same meaning as set forth in the
     Agreement, unless other wise defined.

8.0  Effective January 1, 1997 upon providing Synbiotics with twelve (12) months
     prior written notice, RMI shall have the right to market in the territory,
     FeLV mono and combination vaccines (other than Synbiotics origin). RMI's
     right to sell Synbiotics' FeLV mono and combination vaccines shall become
     nonexclusive nine (9) months after such written notice. When non-exclusive,
     RMI will purchase FeLV at a price no higher than the price offered to any
     other party. The reciprocal shall be true for RMI's origin R-C-P-CHL filled
     containers (see Section 2.1.1 of the Agreement).

9.0  Except as expressly amended by this Addendum, the Agreement remains
     unchanged and in full force and effect. This Addendum may be executed in
     any number of counterparts each of which when so delivered shall be deemed
     an original, but all such counterparts shall constitute one and the same
     instrument.

IN WITNESS WHEREOF, the parties have executed and delivered this Addendum in
Athens, Georgia 22 August 1996.

SYNBIOTICS CORPORATION              RHONE MERIEUX, INC.


By:  /s/ KENNETH M. COHEN           By:  /s/ DON HILDEBRAND
     -------------------------           -----------------------
Title:  President and Chief         Title:  President
        Executive Officer 

Print Name:  Kenneth M. Cohen       Print Name:  Don Hildebrand

Date:  August 22, 1996              Date: August 22, 1996

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