Amylase
and Lipase Values in Potbellied Pigs
Bruce Lawhorn, DVM, MS
The Duchess Fund has
been very proactive in funding projects that aid in the
diagnosis, treatment and prevention of diseases and conditions
of pet pigs. The search for normal laboratory values where
none exists is an example. To be more specific, little or no
information is available on normal amylase and lipase values
in the potbellied pig (PBP). Confirmation of the diagnosis of
pancreatitis depends on these values.
In general,
pancreatitis is rare in swine and it is unknown if (PBP) are
affected. However, pancreatitis is in the differential
diagnostic possibilities for the geriatric PBP that is
presented to a veterinarian with sudden onset of clinical
signs including anorexia, vomiting, painful abdomen, and
reluctance to move.
Serum amylase and
lipase are laboratory tests that are used to help confirm the
diagnosis of acute pancreatitis in other species such as the
dog. In canine acute pancreatitis, serum amylase is usually
elevated within a few hours and back to normal by 2 to 6 days
later; serum lipase is usually elevated after several hours
and remains elevated for 5 to15 days. There is a lack
information on normal values for lipase and amylase in PBPs.
Limited
information for amylase values in domestic swine is available
(The Merck
Veterinary Manual, 8th edition, pages 2192-2193).
In early summer 2003,
the Duchess Fund collected 38 sera from normal adult
PBPs for the purpose of understanding the range of values for
amylase and
lipase. On July 8, 2003, testing was performed on a Hitachi
311 (Roche)
Automated Clinical Chemistry Analyzer in the Clinical
Pathology Department
of the Texas Veterinary Medical Diagnostic Laboratory (TVMDL),
College
Station, Texas.
The mean amylase value
was 2,321 U/L (range: 914 to 5,973U/L). The PBP with
the 5,973 U/L value was an extreme outlier, so when it was
omitted, the mean
amylase value was 2,223 U/L (range:914 to 2,997 U/L).
The mean lipase value
was 30 U/L (range: 7 to 217 U/L).
One problem with
collection of swine blood is red blood cell fragility and
rupture which causes hemolysis, which gives a red tint to
serum. It is
actually difficult for anyone to collect swine blood samples
without having
some hemolysis in the sera.
Extreme hemolysis may
alter amylase and lipase values. On the TVMDL’s scale
of hemolysis of 0 to 4+, all but one of the 38 PBP serum
samples was 3 to 4+
(one sample was 2+). It is thought that greater than 2+
hemolysis will
decrease amylase and possibly inhibit lipase enzyme activity
with the TVMDL
automated testing equipment and procedures.
Therefore, the
limitation to interpretation for these data is the high
amount of hemolysis altering the values (how much alteration
is unknown!).
Nevertheless, a ballpark idea of what serum amylase and lipase
values should
be in normal, adult PBPs is provided. This is particularly
true
considering: the difficulty encountered in obtaining
unhemolyzed sera when
blood sampling swine; and providing any serum samples from
sick PBPs that
are compared to these reference values are run on the same
TVMDL equipment,
using their same procedures.
Barbara Baker
I am my pig's mom!
The Duchess Fund
http://www.duchessfund.org
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