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Israel Journal of Veterinary Medicine  Vol. 70 (1)  March 2015 49 Equine Acute Pancreatitis
INTRODUCTION
Acute pancreatitis is rarely diagnosed in horses and the true
prevalence of the disease is probably under estimated appear-
ing less commonly than in other species (1, 2, 3). It appears to
be much less commonly reported in horses than in other spe-
cies (1). Both acute pancreatitis and chronic pancreatitis have
been documented. Acute pancreatitis is usually associated
with severe acute colic, often characterized as an acute small
intestinal obstruction with signifcant refux and peritonitis.
Chronic pancreatitis tends to cause inappetance, weight loss,
lethargy and mild recurrent signs of colic (1, 2). Previous
studies have identifed horses with gastric distention and/or
rupture with acute pancreatitis (1, 3, 4, 5).
Pancreatitis has been reported to occur in adult horses
although cases of pancreatitis have been described in foals at
post mortem (4, 5, 6, 7). Ante-mortem diagnosis is difcult
on the basis of clinical and laboratory fndings. No specifc
diagnostic tests are available and although reference values
for serum and peritoneal fuid amylase and lipase activities
have been published, their diagnostic accuracy has not been
established (4, 8). Furthermore, trypsin is produced in small
amounts by the equine pancreas (4).
Clinical signs are non-specifc; the most important are
signs of colic, gastrointestinal refux and shock (2-5). Te
abdominal pain originates from gastric distention, peritonitis
and hemoperitoneum (9). Tus the lack of specifc clinical
pathological parameters and clinical signs makes the clinical
diagnosis of equine pancreatitis a challenge in the live horse.
In dogs, cats and humans pancreatitis is associated with
nutritional imbalance, abdominal trauma, hypercalcemia,
hyperlipidemia, drug induced, bacterial and viral infection,
vascular impairment, cholecystitis, small intestinal obstruc-
tion and duodenal refux (9, 10). Etiology in horses includes
partial or complete destruction of the pancreatic duct (chol-
angiohepatitis and cholethiasis), migration of Strongylus
equinus and Parascaris equorum, duodenitis, duodenal ulcers
and possible vasculitis in foals and associated with other
disorders, commonly those involving the gastrointestinal
tract or liver (4, 10, 11). Migration of Strongylus equinus and
Parascaris equorum to the pancreas can produce pancreatic tis-
Acute Pancreatitis in a Horse – a Case Report
Edery, N.,
1
Rosenbaum, A.,
2
Busnach, A.,
1
Steinman, A.,
2
Tirosh Levy, S.
2
and Perl, S.
1
*
1
Department of Pathology, Kimron Veterinary Institute, Beit Dagan, Israel.
2
Koret School of Veterinary Medicine - Veterinary Teaching Hospital, Te Robert H. Smith Faculty of Agriculture, Food and
Environment, Te Hebrew University of Jerusalem, Rehovot, Israel.
*
Corresponding Author: Prof. S. Perl, Department of Pathology, Kimron Veterinary Institute, 50250 Bet Dagan, Israel. Email: perls@moag.gov.il
ABSTRACT
Tis report presents a case of acute pancreatitis in a 30 year old local breed horse. Te horse was diagnosed
clinically with severe acute abdominal pain, distended small intestine, a left dorsal large colon displacement
and large colon impaction. On post mortem examination pathological changes in the pancreas were observed
without intestinal impaction. Histopathologically, the pancreatic lesions were diagnosed as acute pancreatitis
with peripancreatic fat necrosis. In addition to these fndings, multifocal necrotizing hepatitis was identifed
as well as a mild interstitial nephritis and tubular nephrosis. Tis case demonstrates the difculty in making
a clinical diagnosis of pancreatitis in a horse and the importance of a thorough macroscopic and histological
evaluation of the pancreas in horses with a history of abdominal pain.
Keywords: Horse; Colic; Abdomen; Impaction; Pancreas; Pancreatitis; Hepatitis.
Case Reports
Israel Journal of Veterinary Medicine  Vol. 70 (1)  March 2015 Edery, N. 50
sue destruction and extensive fbrosis (12). Histopathology of
acute pancreatitis includes large numbers of neutrophils that
infltrate the pancreatic parenchyma and percolate between
the intralobular septae and acini, the peripancreatic fat shows
evidence of necrosis. Histopathology of chronic pancreatitis
is indicated by marked fbrosis between acinar lobuli and
surrounding the pancreatic ducts. Interstitial mononuclear
cell infltrate may be present (4).
Tis case study describes an adult horse with pancre-
atitis diagnosed at post mortem examination while clini-
cally as a case of severe acute colic that did not respond to
analgesic medication and required abdominal emergency
surgery. Te case illustrates the difculty in the diagnosis
of equine pancreatitis in the clinical situation and proposes
the consideration of pancreatitis as a diferential diagnosis
under conditions of colic of unknown origin.
CASE HISTORY
Clinical history
A 30-year-old local breed horse with an acute abdomen
was admitted to the Koret School of Veterinary Medicine -
Veterinary Teaching Hospital (KSVM-VTH). On physical
examination before referral, the horses demonstrated severe
abdominal pain even after NSAID (fumixin meglumine)
administration and had elevated heart rate (60 beats/minute).
Nasogastric intubation was performed by the referring vet-
erinarian and resulted in spontaneous refux of approximately
25 L of fuid.
Rectal examination revealed swollen small intestines,
large colon displacement and large colon impaction. Prior
to referral the horse received butorphanol, medetomidine
and xylazine. On arrival the horse was dehydrated (dry mucus
membranes and decreased skin turgor). Heart rate was 72/
minute. Passage of a nasogastric tube resulted in 4 liter refux.
Rectal examination at the hospital diagnosed a left dorsal
displacement of the colon and large colon impaction.
Te packed cell volume was 53% (Reference interval (RI)
32-52%), total solids were 8.6 g/dL (RI 5.3-7.9 g/dL). creati-
nine 4.54 mg/dL (RI 0.9-2.0mg/dL) and lactate 7.6 mmol/L
(RI up to 2mmol/L). Te horse was prepared for exploratory
laparotomy, while showing continuous and unrelenting pain.
It was therefore treated with xylazine (Vetmarket, Shoham,
Israel) and butorphanol (Alvegesic, Dachra Veterianary
ptroducts, Shropshire, UK). While preparing the horse, signs
of shock were evident: mean arterial pressure of 20 mm Hg,
weak pulse, disrupted ECG and cyanotic mucous mem-
branes. Prior to induction after consulting with the owners,
the horse was euthanized at the request of the owners due
to the poor prognosis.
Post mortem examination
Te horse was sent for a full post mortem examination. Post
mortem examination revealed slightly collapsed lungs and
fbrous tags on the abdominal surface of the diaphragm. Te
stomach contained sparse fuid content. Te pancreas was
edematous and with multiple white yellowish foci (Figure
1). Te small intestine showed multifocal serosal hemorrhage
for almost its entire length. Te large intestine contained dry
content without pathological lesions in the mucosa. Te liver
and kidney showed no macroscopic pathological changes.
Tere was no evidence of an impaction.
Histopathology
Histopathological examination of the intestines showed en-
gorgement of blood vessels and multifocal serosal hemorrhage
of the small intestine with difuse submucosal edema. In the
pancreatic tissue, multifocal to difuse infltrations by infam-
matory cell mainly neutrophils and histiocytes were present,
as well areas of peripancreatic fat necrosis (Figure 2 and 3). In
some areas intralesinal bacterial colonies could be seen (Figure
4). A few of the kidney’s tubules were distended and contained
an amorphus eosinophilic material. Numerous interstitial
Figure 1: Pancreas: Edema and multiple white yellowish foci of necrosis.
Case Reports
Israel Journal of Veterinary Medicine  Vol. 70 (1)  March 2015 51 Equine Acute Pancreatitis
foci of infammatory mononuclear cells were evident in the
parenchyma. Difuse congestion was present mostly in cortex.
Te liver showed multifocal areas of necrosis and infltrations
with mainly neutrophils. Difuse congestion was also present.
DISCUSSION
Pancreatitis in horses can be a primary condition or may be
associated with other disorders, commonly those involving the
gastrointestinal tract or liver (4). Pancreatitis may be under
diagnosed owing to the presence of nonspecifc abdominal pain.
In this case report, it is unclear and difcult to determine
whether the horse sufered from primary pancreatitis or sec-
ondary pancreatitis associated with hepatitis. Te case history
(pain duration, other symptoms, appetite, etc.) is lacking and
in addition, blood tests including complete blood count and
chemistry are also absent. Laboratory abnormalities associ-
ated with acute pancreatitis include increased activities of
serum (and sometimes peritoneal) amylase and lipase (6).
Te histopathological fnding of multifocal necrotizing
hepatitis has many etiologies: Causes of hepatitis in horses
include serum hepatitis, cholangiohepatitis and chronic active
hepatitis with occasional cases of hematogenous bacterial
hepatitis, abscesses, viral hepatitis, parasitism and chronic
infltrative infammatory disease (7).
It has previously been hypothesized that horses with
enteritis or strangulated small intestinal lesions may develop
acute pancreatitis and hepatitis as a result of ascending infux
of intestinal fuid through the pancreatic and bile duct, with
subsequent activation of pancreatic enzymes (4, 6, 10, 11).
Once activated, these enzymes are responsible for autodiges-
tion of pancreatic tissue, resulting in necrosis of the acini and
pancreatic islets with interstitial fat necrosis and necrotizing
vasculitis. Te release of pancreatic enzymes stimulates the
production of infammatory cytokines, which, in turn triggers
an infammatory cascade which leads to a systemic infamma-
tory response syndrome (SIRS), multiple organ dysfunction
syndrome (MODS), shock and death (4, 8).
Large colon disorders such as volvulus and displace-
Figure 4: Pancreatic necrosis, infltration with infammatory cells and
bacterial colonies. x10
Figure 2: Pancreas: Interlobular edema and infltration with mainly
neutrophils and histiocytes. x20
Figure 3: Pancreas: Peripancreatic fat necrosis and multifocal
infltration with infammatory cells. x20
Case Reports
Israel Journal of Veterinary Medicine  Vol. 70 (1)  March 2015 Edery, N. 52
ments could cause reduced blood fow to the pancreas and
induce pancreatitis (4). In this case report, the rectal exami-
nation diagnosed large colon displacement and obstruction,
but this was not verifed in post mortem examination (5).
Similarly to previous cases, this horse had distended small
intestines and large amount of gastric refux before refer-
ral, signs that are sometimes encountered in acute cases of
pancreatitis (1, 4, 5).
In conclusion, pancreatitis should be considered in horses
with unexplained moderate to severe abdominal pain with or
without gastric refux. Although the ante-mortem diagnosis
of acute pancreatitis in the horse is difcult, it should be
included as a diferential diagnosis. Results from this case
study emphasize the importance of a pathological and his-
topathological evaluation of the pancreas in horses with a
history of abdominal pain.
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Case Reports