research

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

The Endocrine Section
of Michigan State University’s Animal Health Diagnostic
Laboratory was provided the opportunity by the Dutchess Fund
to assist in the development of valid laboratory tests for
thyroid function in Pot Bellied pigs.

The initial phase of
this undertaking included the collection of 50 healthy Pot
Bellied pig serum samples by the Dutchess Fund which were then
forwarded to us at Michigan State University. We analyzed
these samples for their content of total thyroxine (total T4;
the principal thyroid hormone), total triiodothyronine (total
T3), free T4 by equilibrium dialysis (FT4d), and thyrotropin (TSH).

We still have some work
to do in determining how valid our assay systems are for these
analytes. Further work will include the assessment of test
precision (that is how closely do the results agree from the
same sample when it is run numerous times or run on different
days). We also hope to assess the accuracy of our assays (that
is to determine whether we are truly measuring the substance
that we think the assay is measuring).

We have established
temporary reference ranges for these analytes based on our
current understanding of the assay systems we are using:

Analyte	Reference Range
Total T4	18 to 73 nmol/L
Total T3	0.1 to 1.2 nmol/L
Free T4	8 to 36 pmol/L
TSH	0 to 0.13 ng/ml

These
reference ranges could change as we learn more about the
performance of our assays in this species. We are grateful for the
opportunity to work with the Dutchess Fund and hope to provide
additional, useful information in the near future.