Page 578 - Cote clinical veterinary advisor dogs and cats 4th

262 Diarrhea, Chronic

Client Education SUGGESTED READING AUTHOR: Jan S. Suchodolski, MedVet, Dr. med. vet.,
Long-term antibiotic therapy may be required. Suchodolski JS: Diagnosis and interpretation of PhD, DACVM
EDITOR: Rance K. Sellon, DVM, PhD, DACVIM
VetBooks.ir diet control (low-fat, highly digestible) may 37, 2016.
In addition to antibiotic therapy, long-term
intestinal dysbiosis in dogs and cats. Vet J 215:30-
be beneficial.

Diarrhea, Chronic Client Education
Sheet

BASIC INFORMATION loops (mass, adhesions), sausage-shaped intes- • ELISA: Giardia and Cryptosporidium-specific
tinal loop (foreign body, intussusception), antigen; hookworm, roundworm, and
Definition pain (inflammation, obstruction, ischemia, whipworm antigen tests (more sensitive
A persistent (>2-3 weeks) or episodic increase gas), or gas/fluid distention (ileus, fluid, replacement for flotation)
in frequency of defecation, stool fluidity, and/ obstruction). • Routine minimum database: CBC, serum
or fecal volume (increased water content or • Rectal palpation (mandatory unless intracta- biochemical profile, urinalysis (specific
fecal solids) bly painful): mass (polyp, neoplasm, granu- gravity)
loma), circumferential narrowing (stricture, • Cats: retroviral serology, serum thyroxine
Epidemiology spasm, neoplasm), irregular mucosa (colitis, level (>5 years old)
SPECIES, AGE, SEX polyp, neoplasm, perineal fistula)
Any animal can be affected • Observe defecation: tenesmus, dyschezia, Advanced or Confirmatory Testing
character of feces Testing is guided by prior findings. If initial
CONTAGION AND ZOONOSIS • Cats: check for thyroid nodule testing is unremarkable and animal is stable or
See Diarrhea, Acute, Section 1 (p. 257). financial constraints prohibit additional testing,
Etiology and Pathophysiology empirical trial therapy is a reasonable next step.
Clinical Presentation Small intestine: • Pursue clues such as hypoalbuminemia (p.
DISEASE FORMS/SUBTYPES • Decreased fluid and electrolyte absorption 1239) identified on initial testing.
Small-intestinal (SI) diarrhea versus large- • Incomplete nutrient absorption (fats/ • Abdominal imaging
intestinal (LI) diarrhea (p. 1215) or mixed carbohydrates) ○ Radiographs: survey, ± contrast radiography
• Further characterized as maldigestion or • Increased fluid and electrolyte secretion ○ Ultrasonography: mass, thickened bowel,
malabsorption disorders Large intestine: loss of GI wall detail, evaluation of other
• Malabsorption further divided into non– • Decreased fluid and electrolyte absorption abdominal organs
protein-losing enteropathies versus protein- • Secretion of fluid and electrolytes • Baseline cortisol/adrenocorticotropic hormone
losing enteropathies (PLE) • Failure of reservoir function stimulation test (p. 512)
• Trypsin-like immunoreactivity (species-
HISTORY, CHIEF COMPLAINT DIAGNOSIS specific test) (p. 317)
• Signalment, when/where the pet was acquired, • Serum cobalamin (vitamin B 12 ), folate (pp.
vaccinations, medications, anthelmintic use, Diagnostic Overview 1325 and 1344)
dietary and travel history, environment, The list of causes is exhaustive. It is most • Pancreatic lipase immunoreactivity (species-
including other animals, and progression of important to obtain a thorough history and to specific PLI) test (pp. 740 and 742)
clinical signs may help identify triggering consider the pet’s environment and diet before • Infectious disease testing, as appropriate
factors. embarking on tests that may be unwarranted. ○ Fecal cultures (E. coli, Salmonella spp,
• Discrimination between LI and SI causes Every animal should have a rectal exam, fecal C. jejuni, Clostridium spp, Yersinia
will influence the differential diagnosis; many flotation test, and a direct smear performed on enterocolitica): controversial; many of
affected animals have a combination of both fresh fecal samples. these bacteria are commensal organisms;
(p. 1215). see specific organisms/disorders
Differential Diagnosis ○ Molecular techniques (e.g., PCR): often
PHYSICAL EXAM FINDINGS See Diarrhea, Section 3 (p. 1213), for detailed offered as GI or diarrhea panels for
• May appear healthy or may be systemically differential diagnoses. multiple pathogens
ill (e.g., vomiting, depression, weakness, ○ Specific tests, such as histoplasmosis urine
lethargy, dehydration) Initial Database antigen testing (p. 1365)
• Pale mucous membranes: chronic GI blood Fecal examinations: • Occult blood: may reflect chronic blood loss;
loss, anemia of chronic illness/inflammation • Cytology (fresh saline smears): ova, larvae, false-positives possible with meat-based diets.
• Emaciation, dull haircoat suggest malnutri- certain bacteria/protozoa • Gastroduodenoscopy and colonoscopy
tion, chronic malabsorption (fatty acids, ○ Identification of Campylobacter alone is (≈30% of dogs with colitis vomit)
protein, vitamins), neoplasia, PLE. insufficient to make a diagnosis; many • Exploratory laparotomy: full-thickness
• Fever: inflammation, infection, neoplasia are nonpathogenic. biopsies (biopsy even if no gross lesions)
• Dyspnea with decreased lung/heart sounds ○ Iodine stain: enhances visualization of
(pleural effusion), distended abdomen Giardia trophozoites TREATMENT
(ascites), peripheral edema: suggest PLE ○ Low sensitivity for certain parasites (e.g.,
• Abdominal palpation may reveal a mass Tritrichomonas foetus) Treatment Overview
(foreign body, neoplasm, granuloma, abscess, • Flotation/zinc sulfate centrifugation (Giardia The goal of treatment is correction of the
lymphadenomegaly), thickened bowel cysts) underlying cause. For otherwise stable animals,
(inflammation, neoplasia), aggregated bowel • Gram stain empirical therapy may be used as a diagnostic

www.ExpertConsult.com