UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
SCHEDULE 13D
Under the Securities Exchange Act of 1934
(Amendment No. 3)
Synbiotics Corporation
_________________________________________________________________
(Name of Issuer)
Common Stock, no par value
________________________________________________________________
(Title of Class of Securities)
87156610
________________________________________________________________
(CUSIP Number)
Roger A. Keller, 7733 Forsyth Blvd., St. Louis, MO 63105
(314) 854-5244
_________________________________________________________________
(Name, Address and Telephone No. Of Person
Authorized to Receive Notices and Communications)
July 22, 1997
________________________________________________________________
If the filing person has previously filed a statement on Schedule 13G
to report the acquisition which is the subject of this Schedule 13D, and
is filing this schedule because of Rule 13d-1(b) (3) or (4), check the
following box. / /
Note: Six copies of this statement, including all exhibits, should be
filed with the Commission. See Rule 13d-1(a) for other parties to whom
copies are to be sent.
*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 disclosures provided in a prior cover page.
The information required on 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).
<PAGE>
SCHEDULE 13D
CUSIP No. 87156610 Page 2 of 4
___________________________________________________________________
1. NAME OF REPORTING PERSON
S.S. or I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
Mallinckrodt Inc. 36-1263901
__________________________________________________________________
2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) / /
(b) / /
N/A
__________________________________________________________________
3. SEC USE ONLY
__________________________________________________________________
4. SOURCE OF FUNDS
00
__________________________________________________________________
5. CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS
IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e)
N/A / /
__________________________________________________________________
6. CITIZENSHIP OR PLACE OF ORGANIZATION
New York
__________________________________________________________________
7. SOLE VOTING POWER
NUMBER OF 465,639
SHARES __________________________________________________
BENEFICIALLY 8. SHARED VOTING POWER
OWNED BY N/A
EACH __________________________________________________
REPORTING 9. SOLE DISPOSITIVE POWER
PERSON 465,639
WITH __________________________________________________
10. SHARED DISPOSITIVE POWER
N/A
__________________________________________________________________
11. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
465,639
__________________________________________________________________
12. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES
CERTAIN SHARES / /
N/A
__________________________________________________________________
13. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)
6.3%
__________________________________________________________________
14. TYPE OF REPORTING PERSON
CO
__________________________________________________________________
Item 1. Security and Issuer.
- -----------------------------
This statement relates to the Common Stock, no par value (the
"Common Stock"), of Synbiotics Corporation, a California corporation
(the "Issuer"), whose executive offices are located at 11011 Via
Frontera Drive, San Diego, CA 92127.
<PAGE>
CUSIP No. 87156610 Page 3 of 4
Item 2. Identity and Background.
- ---------------------------------
Mallinckrodt Inc. is a New York corporation ("Mallinckrodt") whose
principal business is the production and sale of specialty
pharmaceutical and highly selected specialty industrial chemicals; and
the production and sale of human health products in the fields of
cardiology, radiology, anesthesiology, nuclear medicine and critical
care. Mallinckrodt's principal office is located at 7733 Forsyth
Boulevard, St. Louis, Missouri 63105.
During the last five years, neither Mallinckrodt nor any of its
executive officers, directors or controlling persons has been convicted
in a criminal proceeding (excluding traffic violations or similar
misdemeanors).
During the last five years, neither Mallinckrodt nor any of its
executive officers, directors or controlling persons has been and is not
now (a) subject to a judgment, decree or final order enjoining future
violations of, or prohibiting or mandating activities subject to,
federal or state securities laws, or (b) a party to a civil proceeding
of a judicial or administrative body of competent jurisdiction finding
any violation with respect to such laws.
Item 3. Source and Amount of Funds or Other Consideration.
- -----------------------------------------------------------
No change from information in Mallinckrodt's prior filings on
Schedule 13D with respect to the Common Stock.
Item 4. Purpose of Transaction.
- --------------------------------
No change from information in Mallinckrodt's prior filings on
Schedule 13D with respect to the Common Stock.
Item 5. Interest in Securities of the Issuer.
- ----------------------------------------------
(a) Mallinckrodt beneficially owns an aggregate of 465,639 shares of
Common Stock of the Issuer, representing approximately 6.3% of the
issued and outstanding shares of the Common Stock.
(b) Mallinckrodt has voting and dispositive power with respect to
465,639 shares of the Common Stock.
(c) Mallinckrodt engaged in the following sales of the Common Stock in
the past 60 day period ending on July 22, 1997:
Date Shares Price Where
July 1, 1997 1,000 4.000 Open market
July 2, 1997 1,000 4.000 " "
July 3, 1997 1,000 4.250 " "
July 7, 1997 1,000 4.000 " "
July 8, 1997 1,000 4.000 " "
July 9, 1997 1,000 4.000 " "
July 10, 1997 1,000 4.250 " "
July 11, 1997 1,000 4.250 " "
July 14, 1997 800 4.250 " "
July 14, 1997 200 4.375 " "
July 15, 1997 1,000 4.250 " "
July 16, 1997 1,000 4.063 " "
July 17, 1997 1,000 4.000 " "
July 18, 1997 1,000 4.063 " "
July 21, 1997 1,000 4.125 " "
July 22, 1997 1,000 4.250 " "
(d) Mallinckrodt has the right to receive dividends from or the proceeds
from the sale of the Common Stock.
(e) Not applicable.
Item 6. Contracts, Arrangements, Understandings or
Relationships with Respect to Securities of the Issuer.
- -----------------------------------------------------------------
No change from information contained in Mallinckrodt's prior
filings on Schedule 13d with respect to the Common Stock.
Item 7. Material to be Filed as Exhibits.
- ------------------------------------------
No change from exhibits filed with Mallinckrodt's prior filings on
Schedule 13D with respect to the Common Stock.
Signature
---------
After reasonable inquiry and to the best of my knowledge and
belief, the undersigned certifies that the information set forth in this
statement is true, complete and correct.
Date: August 15, 1997
MALLINCKRODT INC., a New York corporation
By:____________________________
Name: Roger A. Keller
Title: Vice President, Secretary & General
Counsel
