Page 634 - Clinical Small Animal Internal Medicine

602 Section 6 Gastrointestinal Disease

Table 56.1 Historical and clinical findings in cats with confirmed disease show this form of pancreatic infiltrate.
VetBooks.ir Remarkably, at least one necropsy‐based study of cat
pancreatic inflammatory disease
pancreata has suggested that signs of pancreatic inflam­
total cases reported)
Clinical sign Frequency (#cats/ Frequency mation, including lymphocytic‐plasmacytic infiltration
(% of cats)
and fibrotic change, are common in cats with no history
suggestive of pancreatic disease.
Reduced appetite 113/136 83 One problem with the terminology of pancreatitis,
Lethargy 105/136 77 particularly the distinction of acute vs chronic pancreati­
Dehydration 88/136 65 tis, is the implication of differing chronologies of the dis­
Vomiting 58/136 43 ease. This is particularly problematic in the feline patient.
Abdominal pain 27/73 36 While it is generally safe to assume that cats with longer
Icterus 40/136 29 histories of recurrent clinical signs such as lethargy,
Weight loss 22/96 16 decreased appetite, and recurrent vomiting do indeed
have chronic pancreatitis, the converse is not necessarily
true. Given the subtle nature of clinical signs and histori­
of pancreatitis. This may be due to the tendency of feline cal complaints in many cats with pancreatic disease, and
patients to “hide” clinical signs, the relatively subtle the waxing/waning nature of clinical signs in most
nature of pain manifestation in many cats, and a ten­ chronic lympho‐plasmacytic diseases, it is not valid to
dency to interpret struggling or resisting examination as assume that a cat with a new presentation of relatively
a normal response on the part of feline patients. Often, acute clinical signs actually has “acute pancreatitis” as
the most important findings on physical examination in defined histologically. As discussed earlier, there is no
feline patients with pancreatitis are signs and symptoms reliable way to distinguish necrotizing or hemorrhagic
of co‐morbid disease (palpably thickened gastrointesti­ pancreatitis from lympho‐plasmacytic disease in feline
nal tract, icterus, poor body condition), or findings that patients. Therapeutic decision making should be based
are important in the assessment of the overall state of on assessment of the overall state of health of the patient
health of the patient (state of hydration, presence of free on presentation, rather than assumptions that a patient
abdominal fluid, alterations in body temperature). As may or may not have a particular form of the disease.
with the histories of cats with pancreatitis, these vague,
diffuse, and nonspecific findings in most cats with pan­
creatic inflammatory disease mean that pancreatic dis­ Noninvasive Diagnostics for Feline
ease is a reasonable differential diagnosis in essentially Pancreatitis
any cat that presents unwell.

Routine Clinical Chemistries
Characterization of Pancreatitis in the Cat
Routine clinical chemistry and complete blood count
Typically, pancreatitis has been divided into acute and (CBC) evaluations are a critical part of the approach to
chronic diseases, based on histologic differences in any unwell feline patient. In the context of cats with a
human and canine patients. Generally speaking, “acute suspicion of pancreatitis, the most important aspect of
pancreatitis” is either neutrophilic or hemorrhagic and is the routine chemistry panel and CBC is the assessment
associated with rapid onset of severe symptoms, marked of the overall physiology of the patient. There are very
abdominal pain and potentially life‐threatening acid– few to no findings on routine clinical pathology panels
base and electrolyte disturbances. By comparison, that can be considered highly sensitive or specific for
“chronic pancreatitis” is typically associated with fibrous pancreatitis in the cat. One exception to this would be
replacement of pancreatic tissue and the presence of a the “pancreas‐specific lipase” assays that are beginning
lymphocytic inflammatory infiltrate. Although chronic to be promoted more heavily in some routine chemistry
pancreatitis is being recognized more frequently in panels, and are discussed in more detail later.
canine patients, most clinicians consider acute pancrea­ In the dog and human patients, traditionally we have
titis to be the most common form of the disease in dogs. relied on the measurement of serum amylase and lipase
In cats, chronic pancreatitis is the most commonly activities to establish a diagnosis of pancreatitis, with the
diagnosed disease following histologic assessment of expectation that these activities will be markedly elevated.
pancreatic biopsies. As in humans and dogs, this diagno­ While these tests are admittedly low sensitivity and speci­
sis is based on the presence of lymphocytic or plasma­ ficity in both dogs and people, marked elevations in
cytic cellular infiltrates and, typically, some degree of patients with compatible clinical signs are at least strongly
fibrosis. In some studies, >80% of cats with pancreatic supportive of the clinical suspicion of pancreatitis.