Rule 424(b)(3)
                                                      Registration No. 333-42763

                             PROSPECTUS SUPPLEMENT

                             SYNBIOTICS CORPORATION

This prospectus supplement is dated December 7, 1998.  It relates to the
Prospectus, dated December 19, 1997, of Synbiotics Corporation under a
registration statement on Form S-8, registration number 333-42763.

In September 1998 Synbiotics declared a dividend on each share of Common Stock
(including the Shares) outstanding on October 7, 1998.  The per-share dividend
consisted of one Right to purchase, for $10.00, 1/1000th of a share of
Synbiotics' Series A Junior Participating Preferred Stock.  The dividend was
paid on October 7, 1998 and was part of Synbiotics' implementation of a "poison
pill" shareholder rights plan.

Until a triggering acquisition-oriented event (as defined in Synbiotics' Rights
Agreement), each of the Rights is paired with and will trade inseparably with
one share of Synbiotics Common Stock.  Accordingly, each of the Shares sold
under this Prospectus will include not only a share of Common Stock but also the
Right which is paired with it.

A complete description of the Rights is included in Synbiotics' registration
statement on Form 8-A filed on October 7, 1998, which has been incorporated by
reference into this Prospectus.