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Abdominal Distention 2.e3

Abdominal Distention Client Education
Sheet
VetBooks.ir Diseases and Disorders

BASIC INFORMATION
HISTORY, CHIEF COMPLAINT ○ Intestine
Ileus
■
Definition • Abdominal enlargement may be apparent ■ Feces (e.g., obstipation)
Expansion or enlargement of the abdominal or discrete. ○ Uterus
cavity from any cause • Abdominal enlargement may be acute or ■ Pyometra
insidious. ■ Pregnancy
Epidemiology • Marked abdominal distention may cause ○ Urinary bladder
SPECIES, AGE, SEX respiratory effort (especially with severe or ■ Urethral obstruction
Varies, depending on the underlying cause: sudden fluid accumulation). ■ Bladder dysfunction (e.g., detrusor
• Neoplastic mass: older animals • Marked abdominal distention may cause atony, dysautonomia)
• Feline infectious peritonitis: young cats hyporexia with or without vomiting. ○ Hepatomegaly
• Hyperadrenocorticism: older dogs > cats • A wide variety of additional complaints ○ Splenomegaly
may be recognized, depending on the ○ Renomegaly
GENETICS, BREED PREDISPOSITION underlying cause for abdominal distention
Some causes of abdominal distention may have (e.g., unproductive retching due to gastric DIAGNOSIS
a breed predisposition, but many others do dilation/volvulus, urinary incontinence due
not: to detrusor atony). Diagnostic Overview
• Ascites related to History and physical examination should guide
○ Protein-losing enteropathy: Yorkshire PHYSICAL EXAM FINDINGS the choice of diagnostic testing with the objec-
terrier, soft-coated wheaten terrier, basenji, • Body condition score and muscle condition tive being to determine the underlying cause
Norwegian lundehund help distinguish obesity from other causes of distention. In some cases (e.g., palpation of
○ Protein-losing nephropathy: Shar-pei, of abdominal distention. a pregnant uterus), additional testing may not
soft-coated wheaten terrier • Abdominal palpation may reveal be required.
○ Dilated cardiomyopathy: Doberman ○ Organomegaly
pinscher, cocker spaniel ○ Intra-abdominal mass Differential Diagnosis
• Gastric dilation/volvulus: large-breed, deep- ○ Fluid wave See Abdominal Distention (p. 1192).
chested dogs are predisposed. ○ Poor muscle tone
• Splenic hemangiosarcoma: German shepherd, ○ Severe bladder distention Initial Database
retrievers, boxer ○ Abdominal discomfort or pain CBC, serum chemistry profile, urinalysis,
○ Pregnant or fluid-filled uterus and abdominal imaging studies are often
RISK FACTORS ○ Tense abdomen with indistinguishable useful in determining a cause of abdominal
• Any cause of hypoalbuminemia may lead to contents distention.
ascites. • Tachypnea ± respiratory effort due to pressure If palpable fluid wave, consider
• Lack of heartworm prophylaxis may lead to on diaphragm • Abdominocentesis is typically required for
right heart failure. • Additional abnormalities related to cause of diagnostic purposes (fluid analysis with
• Excessive caloric intake and inadequate abdominal distention (e.g., heart murmur cytology ± culture). Type of fluid will
exercise may lead to obesity. and jugular pulse related to right-sided heart determine differential diagnosis and addi-
• Exposure of an intact female to an intact failure, bilaterally symmetrical truncal alo- tional diagnostic testing.
male can result in pregnancy. pecia related to hyperadrenocorticism) • Serum chemistry and urinalysis: indicated
• Chronic use of high-dose glucocorticoids can to rule out hypoalbuminemia, proteinuria
result in iatrogenic hyperadrenocorticism. Etiology and Pathophysiology as cause of transudate
• Hypercoagulability can result in portal Abdominal distention may be the result of ○ Catheterized or midstream catch urine
thrombus formation with subsequent portal diverse conditions: collection appropriate
hypertension. Obesity • Abdominal imaging
Pregnancy ○ Radiographs; utility limited due to loss
CONTAGION AND ZOONOSIS Loss of abdominal muscle tone (e.g., of serosal detail
Some causes of abdominal distention are caused hyperadrenocorticism) ○ Ultrasonography is not hampered by fluid.
by infectious disease (e.g., feline infectious Free abdominal fluid • Specific additional tests may be indicated;
peritonitis), but most are not. ○ Transudate for example,
○ Modified transudate ○ If murmur or jugular pulses detected,
ASSOCIATED DISORDERS ○ Exudate (any type) consider thoracic radiographs, echocar-
Tachypnea, increased respiratory effort, hypo- Intra-abdominal mass diogram, heartworm antigen test to rule
rexia, vomiting ○ Non-neoplastic out right-heart failure.
Clinical Presentation ■ Abscess ○ If proteinuria recognized, urine protein/
■ Granuloma creatinine ratio indicated, and consider
DISEASE FORMS/SUBTYPES ■ Lipoma thromboelastography, prothrombin time/
Abdominal distention may be the chief ■ Reactive lymphadenopathy partial thromboplastin time (PT/PTT) to
concern, and pets may be presented for ○ Neoplasia (of any abdominal tissue) rule out hypercoagulability leading to
perceived weight gain, even in the presence Organ distention portal thrombus.
of cachexia. Alternatively, another (causative) ○ Stomach ○ If severe hypoalbuminemia recognized
disorder may prompt the veterinary visit, with ■ Gastric dilation ± volvulus with low globulins, intestinal biopsy may
abdominal distention recognized on physical ■ Ingesta be warranted to identify cause of protein-
examination. ■ Gastrointestinal parasites losing enteropathy.

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