By Shana Buchanan, DVM, MBA,
Certified Veterinary Acupuncturist,
Certified in Veterinary Chiropractic, Certified in Veterinary Chinese Herbal
Medicine, Veterinary Food Therapist
Hopefully,
during the holiday season your four-legged children stayed healthy. The little bits of table scraps or little
tastings of the food that is available during the holidays can cause a severe
stomach ache, pancreatitis, to your canine family members. To avoid this problem in the future, I will
explain what it is, the symptoms to watch for, and the treatment for the acute
condition. If you have any questions or
concerns regarding this condition, please, call the Animal Hospital of
Montgomery at 935.582.1555.
The
Normal Pancreas and What it Does
We eat food, chew it
up into slurry, and swallow it. It travels down the esophagus to the stomach
where it is ground up further and enzymes are added to begin the breakdown of
dietary nutrients (digestion). When the food particles are small enough, they
are propelled into the small intestine for further digestive treatment and
ultimately nutrient absorption.
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The small intestine
has three portions: the duodenum that connects to the stomach and the jejunum
and ileum below. The jejunum and ileum are mostly involved in absorption but
the duodenum, being so close to the stomach, is the site of further digestion.
There are two ducts
that enter the duodenum near where the stomach contents enter. One duct is for
bile, squirted in directly from the liver's gall bladder. The bile serves to
neutralize the acid that the stomach had added to emulsify (or dissolve)
dietary fats for absorption later in the tract, and also to excrete some
toxins. The other duct is the pancreatic duct, which squirts in more digestive
enzymes so as to break down starches and continue the breakdown of protein.
The pancreas is a
pale pink glandular organ that nestles cozily just under the stomach and along
the duodenum. As a glandular organ, the pancreas is all about secretion and it
has two main jobs: the first job is the secretion of digestive enzymes to help
us break down the food we eat, the second job is the secretion of insulin and
glucagon (to regulate sugar metabolism). The digestive enzymes are the part of
the story that concerns us in pancreatitis.
Pancreatitis
is Inflammation of the Pancreas
In pancreatitis,
inflammation disrupts the normal integrity of the pancreas. Digestive enzymes
that are normally safely stored in granules are released prematurely where they
digest the body itself. The result can be a metabolic catastrophe. The living
tissue becomes further inflamed and the tissue damage quickly involves the
adjacent liver. Toxins released from this orgy of tissue destruction are
released into the circulation and can cause a body-wide inflammatory response.
If the pancreas is affected so as to disrupt its ability to produce insulin, diabetes mellitus
can result; this can be either temporary or permanent.
Specific
Pancreatitis Disasters
Specific disasters
include the disruption of surfactants in the lung tissue that normally keep the
tiny air-filled alveoli from collapsing after each exhaled breath. Without
surfactants, the alveoli close up and respiratory failure results.
Also, there is a
syndrome called Weber-Christian syndrome where fats throughout the body are
destroyed, which has painful and disastrous results.
Pancreatitis is one
of the chief risk factors for the development of what is called disseminated
intravascular coagulation, or DIC, which is basically a massive uncoupling of
normal blood clotting and clot dissolving mechanisms. This uncoupling leads to
abnormal simultaneous bleeding and clotting of blood throughout the body.
Pancreatic
encephalopathy (brain damage) can occur if the fats protecting the central
nervous system become digested.
The good news is that
most commonly the inflammation
is confined to the area of the liver and pancreas,
but even with this limitation pancreatitis can be painful and life-threatening.
is confined to the area of the liver and pancreas,
but even with this limitation pancreatitis can be painful and life-threatening.
Pancreatitis can be
acute or chronic, mild or severe.
What
Causes Pancreatitis
In most cases we
never find out what causes it but we do know some events that can cause
pancreatitis:
- Reflux of duodenal contents into
the pancreatic duct. The pancreas has numerous safety mechanisms to
prevent self-digestion. One mechanism is storing the enzymes it creates in
an inactive form. They are harmless until they are mixed with activating
enzymes. The strongest activating enzymes are made by duodenal cells; the
digestive enzymes do not activate until they are out of the pancreas and
mixing with food in the duodenum. If duodenal fluids backwash up the
pancreatic duct and into the pancreas, enzymes are prematurely activated
and pancreatitis results. This is apparently the most common pancreatitis
mechanism in humans, though it is not common in veterinary patients.
- Concurrent hormonal imbalance
predisposes a dog to pancreatitis. Such conditions include: diabetes mellitus, hypothyroidism, and hypercalcemia. The first two conditions are
associated with altered fat metabolism, which predisposes to pancreatitis,
and the second condition involves elevated blood calcium that activates
stored digestive enzymes.
- Use of certain drugs can
predispose to pancreatitis (sulfa-containing antibiotics such as trimethoprim sulfa, chemotherapy agents such as azathioprine or L-asparaginase, and the anti-seizure medication potassium bromide). Exposure to organophosphate
insecticides has also been implicated as a cause of pancreatitis. Exposure
to steroid hormones have traditionally been thought to be involved as a
potential cause of pancreatitis but this appears not to be true, though
steroids are able to cause an increase in lipase blood tests.
- Trauma to the pancreas that occurs
from a car accident or even surgical manipulation can cause inflammation
and thus pancreatitis.
- A tumor in the pancreas can lead
to inflammation in the adjacent pancreatic tissue.
Miniature Schnauzers
are predisposed to pancreatitis as they commonly have altered fat metabolism.
Signs
of Pancreatitis
The classical signs
in dogs are appetite loss, vomiting, diarrhea, painful abdomen, and fever.
Making
the Diagnosis
A reliable blood test
has been lacking for this disease until recently. Traditionally, blood levels
of amylase and lipase (two pancreatic digestive enzymes) have been used. When
their levels are particularly high, it is a reasonable sign that these enzymes
have leaked out of the pancreas and pancreatitis is present; still, these tests
are not as sensitive or specific as we would prefer. Amylase and lipase can
elevate dramatically with corticosteroid use, with intestinal perforation,
kidney disease, or even dehydration. Some experts advocate measuring lipase and
amylase on fluid from the belly rather than on blood but this has not been
fully investigated and is somewhat invasive.
A newer test called
the PLI or pancreatic lipase immunoreactivity test has come to be important. As
mentioned, lipase is one of the pancreatic digestive enzymes and only small
traces are normally in circulation. These levels jump dramatically in
pancreatitis and the diagnosis can be confirmed with a less expensive and
non-invasive test. A regular lipase level measures all forms of lipase, not
just those of a pancreatic source; this is test is specific for pancreatic
lipase. The problem is that the technology needed to run this test is unique
and the test can only be run in certain facilities on certain days. Results are
not necessarily available rapidly enough to help a very sick patient.
More recently a new
test called the SPEC cPL (specific canine pancreatic lipase) test has come to
be the test of choice. This test is a newer generation immunological test for
canine pancreatic lipase and can be run overnight by a reference lab. This test
is able to detect 83% of pancreatitis cases (the test is 83% sensitive) and
excludes other possible diseases in 98% of cases (i.e. the test is 98% specific
for pancreatitis). There is no comparable test for cats at this time.
Radiographs can show
a widening of the angle of the duodenum against the stomach, which indicates a
swelling of the pancreas. Most veterinary hospitals have the ability to take
radiographs but this type of imaging is not very sensitive in detecting
pancreatitis and only is able to find 24% of cases.
Ultrasound, on the
other hand, detects 68% of cases and provides the opportunity to image other
organs and even easily collect fluid from the belly. Since pancreatitis can be
accompanied by a tumor near the pancreas, ultrasound provides the opportunity
to catch such complicating factors.
In some cases,
surgical exploration is the only way to make the correct diagnosis.
Treatment
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The passage of food
through the duodenum is a strong stimulus to the pancreas. In the treatment of
canine pancreatitis we do not want any stimulation of the pancreas; we want the
pancreas to rest. This means no food and no water for 2 to 3 days (IV fluid support
prevents dehydration).
Fluid support will
generally require potassium supplementation because potassium depletes in
pancreatitis. Blood pH must be tracked as well. A critical patient with
pancreatitis may need 24 hour care and blood test monitoring several times a
day. A plasma transfusion represents a specific type of fluid therapy and helps
provide certain proteins that inhibit pancreatic enzymes. Whether or not the
protection afforded by plasma is real or theoretical is still being worked out,
but since it is difficult to go wrong with a plasma transfusion, do not be
surprised if your veterinarian uses this approach.
Pancreatitis is a
painful condition and pain management is not only humane but important in
recovery. Untreated pain affects the immune system and increases mortality.
Injectable pain medications, fentanyl patches, and even continuous drips can be
used effectively to control pain. Additional medication to control nausea is
also commonly used. Antibiotics are often used because even though pancreatitis
is not a bacterial disease, bacterial invasion from the diseased intestine is a
common occurrence.
Once the patient has
started to eat again, a low fat diet, such as one of the prescription high
fiber diets, is important to minimize pancreatic stimulation. Since there is
potential for the pancreas to always have a chronic smoldering bit of
inflammation, long-term use of a low fat diet is likely to be recommended.
Beware of Diabetes Mellitus
Beware of Diabetes Mellitus
When the inflammation
subsides in the pancreas, some scarring is inevitable. When 80% of the pancreas
is damaged, insulin cannot be produced, and diabetes mellitus results. This may
or may not be permanent depending on the capacity for the pancreas's tissue to
recover. See more information on the management of diabetes mellitus.
References
Brooks, Wendy (Janurary 2006). Canine Pancreatitis. Client Handout. Veterinary Information
Network. VIN
Community Contributors.
Retrieved from www.vin.com on November 27, 2012.
