Page 989 - Small Animal Clinical Nutrition 5th Edition

1026 Small Animal Clinical Nutrition

but should be considered. Gastric parasites, such Ollulanus tri-
VetBooks.ir cuspis or Physaloptera spp., are identified more readily in vomi-
tus or gastric juice or on endoscopic visualization. The accura-
cy of fecal occult blood testing has been confirmed in dogs con-
suming dry foods (Dow et al, 1990; Gilson et al, 1990). Moist
meat-based foods often yield false-positive results. Both the
modified guaiac and orthotoluidine tests are sensitive and spe-
cific for detecting occult blood in feces (Gilson et al, 1990).
Imaging modalities (e.g., survey and contrast radiography
and ultrasonography) are noninvasive diagnostic techniques for
evaluating pets with gastritis or GI ulceration. Abdominal radi-
ographs frequently are normal in patients with gastritis (Simp-
son, 2005). Survey radiography may be useful in the diagnosis
of radiopaque foreign bodies. Abnormalities in renal size or
Figure 52-1. Endoscopic appearance of antral gastritis in a dog
with chronic vomiting. Note the multiple hemorrhagic erosive lesions shape may suggest renal insufficiency as the cause of gastritis.
of the gastric mucosa. (Courtesy Dr. Michael Leib, Virginia-Maryland Hepatosplenomegaly in cats suggests systemic mastocytosis or
Regional College of Veterinary Medicine, Blacksburg, VA.) alimentary lymphosarcoma. Free air in the abdomen is diag-
nostic for viscus rupture associated with a perforated GI ulcer
and indicates the need for immediate exploratory surgery.
assumes a “praying posture,” which is considered a manifesta- Contrast radiographic examinations may be useful. Iodinated
a
tion of upper abdominal pain. contrast agents should be used if GI perforation is suspected.
Patient history often is adequate to provide a presumptive Otherwise, barium sulfate is the contrast agent of choice for GI
diagnosis of gastritis. Owners should be questioned closely studies because of its superior ability to coat the GI mucosa.
about potential for toxin exposure (e.g., lead, arsenic) and for- More complete descriptions of radiographic findings in gastric
eign body ingestion (e.g., bones, coins, garbage) by the patient. disease are available (Moon and Myer, 1986).
A history of NSAID administration provides a presumptive Endoscopic examination is the most sensitive test for detec-
diagnosis of drug-induced gastroduodenal erosions or ulcera- tion of gastritis and gastroduodenal ulcerative disease. Gastric
tions. The veterinarian should question the owner specifically fluid can be collected for parasitic and microbiologic examina-
about the use of over-the-counter agents (e.g., aspirin, ibupro- tion. Endoscopic evaluation allows for the identification of
fen) in addition to prescription NSAIDs. mucosal and submucosal hemorrhages, erosions and ulcers,
Physical examination is often unremarkable in dogs and cats tumors and foreign bodies (Figure 52-1). Gastric and duodenal
with gastritis or gastroduodenal ulcerations. Reduced skin tur- biopsy specimens for histopathologic examination and brush
gor and tacky mucous membranes indicate dehydration. Ab- cytology samples can be collected endoscopically (Jergens et al,
dominal pain may be recognized, particularly in those patients 2000). Helicobacter spp. can be identified in impression smears
that develop peritonitis as a consequence of a perforated ulcer. prepared from such samples (Simpson, 2005). Gastric biopsy
In chronic cases, weight loss and poor body condition may be specimens can be evaluated for Helicobacter spp. using the rapid
b
noted. Pallor and weakness may be present in patients with sig- urease test (Leib and Duncan, 2005).
nificant gastrointestinal (GI) blood loss. Other findings may
reflect the underlying cause of gastritis (e.g., cutaneous masses Risk Factors
or hepatosplenomegaly associated with mastocytosis). Dogs with liver or kidney disease, hypoadrenocorticism, spinal
cord disease, shock, stress, neoplasia, mastocytosis and systemic
Laboratory and Other Clinical Information disease are at increased risk for gastroduodenal ulceration
Routine hematology, serum biochemistry profiles and urinaly- (Lascelles et al, 2005; Simpson, 2005; Henderson and Webster,
ses help rule out metabolic causes of gastritis. These tests read- 2006).
ily identify renal disease, hepatopathies and hypoadrenocorti- Older pets are more likely to be suffering from metabolic or
cism. The hematocrit and hemogram are useful in assessing neoplastic causes of gastritis. Dogs of any age receiving
severity and chronicity of gastric disease. Inflammatory leuko- NSAIDs, corticosteroids, or both, for management of
grams may be identified in animals with neoplasia, perforated osteoarthritis are at risk for gastritis and gastroduodenal
GI ulcers, inflammatory bowel disease (IBD) and pythiosis. ulceration.
Eosinophilia may indicate parasitism or eosinophilic gastritis. Younger dogs and cats and unsupervised pets are more like-
In cats, extreme eosinophilia is suggestive of hypereosinophilic ly to suffer from gastritis secondary to foreign bodies or dietary
syndrome or systemic mastocytosis. Identification of circulating indiscretion. Several breed-associated causes of gastritis have
mast cells is generally diagnostic for mast cell tumors, which are been recognized (Table 51-1). Dachshunds, miniature schnau-
associated with GI ulcer disease due to hyperhistaminemia. zers, toy poodles and other small- and toy-breed dogs are most
Fecal examinations for parasites and occult blood are impor- commonly affected with hemorrhagic gastroenteritis (Guilford
tant screening tests. Parasites are an unlikely cause of gastritis, and Strombeck, 1996). Several breeds are at risk for chronic