Contributors: Steven Marks, Elisa Mazzaferro, Zoe Halfacree

 Species: Feline   |   Classification: Diseases

Introduction Pathogenesis Diagnosis Treatment Outcomes Further Reading


  • Acute onset of abdominal pain.
  • Prompt diagnosis and immediate medical or surgical intervention necessary to prevent deterioration of patient.

Presenting Signs

  • Abdominal pain/abdominal splinting.
  • Vomiting.
  • Diarrhea.
  • Postural changes.
  • Gait changes: stiff stilted gait.
  • Reluctance to move.
  • Hiding from owners.
  • Anorexia.
  • Lethargy.
  • Shock.

Age Predisposition



  • Depends on primary cause.
  • Sources of abdominal pain include the following systems:
    • Urogenital, eg ureteric obstruction due to ureterolithiasis Urolithiasis.
    • Gastrointestinal, eg small intestinal obstruction.
    • Splenic.
    • Hepatobiliary.
    • Pancreatic.
    • Peritoneal.
  • Displacement, obstruction or distention, inflammation or infection, perforation or rupture, and/or vascular compromise in any of these systems can result in somatic or visceral pain and the presentation of an acute abdomen.


  • Abdominal pain caused by distention/stretch, inflammation or ischemia of solid or hollow abdominal organs, mesentery or parietal peritoneum.
  • Ischemia and inflammation can also result in activation of pain receptors via the release of mediators such as bradykinin, serotonin, histamine and eicosanoids.


  • Acute onset.


  • Signalment and history can aid in helping focus on most likely diagnosis.


Presenting Problems

  • Immediate questions to ask yourself:
    • Does the patient require IMMEDIATE resuscitation?
    • Does the patient require invasive cardiorespiratory monitoring?
    • Are diagnostic tests necessary?
    • Does the patient require urgent surgery?
    • Does the patient require a surgical work-up?

Client History

  • Ask client specific questions:
    • Toxin exposure? (ethylene glycol Ethylene glycol poisoning, other).
    • Garbage ingestion or dietary indiscretion (deliberate or accidental).
    • Foreign body exposure?
    • Possibility of trauma?
    • Nature and character of vomit? In relation to meals/eating?
    • Vaccination status.
    • Health status of other animals or humans in household?
    • Type, dose and duration of any drugs (NSAIDs Analgesia: NSAID, steroids, acetaminophen, diazepam Diazepam)?
    • Recent heat cycle in unspayed female cats?

Clinical Signs

Physical examination

  • Perform a thorough physical examination.
    Perform abdominal examination LAST, as it can be painful and may lead you to miss vital clinical signs.


  • Eyes:
    • Sunken, anisocoria (trauma or toxin), mentation, seizures (metabolic or toxin).
  • Tongue:
    • Look carefully under the tongue for the presence of string/linear foreign bodies. As it may cut in deep under the tongue careful inspection is needed.
  • Fur around muzzle:
    • Look for evidence of excessive salivation (nausea).
    • Look at fur around muzzle for evidence of vomit or toxin (Wood's lamp used to detect ethylene glycol. Ethylene glycol may fluoresce under a black light/Wood's lamp Wood''s lamp test).
  • Mucous membranes:
    • Color.
    • Tachyness.
    • Capillary refill time.
    • Rapid CRT with endotoxin/sepsis.
    • Prolonged CRT with hypovolemic shock.

Thoracic auscultation

  • Lungs Respiratory: disease - clinical investigation:
    • Normal or harsh/crackles (aspiration pneumonitis secondary to vomiting?).
    • Respiratory rate and effort.
  • Cardiac Heart: disease - clinical investigation:
    • Murmurs?
    • Arrhythmias? (severe bradycardia if hyperkalemia and atrial standstill present with urinary tract obstruction or rupture).
    • Pulse quality and character/synchrony.
      • Bounding pulses with endotoxic/septic shock Shock: septic.
      • Poor pulse quality with hypovolemic shock.
    • Vomiting may precede signs of cardiac disease by several days.

Neurological examination

  • In stable patients, perform complete neurological examination Neurological examination:
    • Cranial nerves: decreased function.
    • Gait abnormalities: intervertebral disk disease can be mistaken for abdominal pain Intervertebral disk disease.
    • Mentation: dull depressed with shock, trauma, seizures, toxins.


  • Look carefully for evidence of penetrating trauma, blood on haircoat.
  • Look carefully for evidence of bruising or hemorrhage.
  • Look carefully at skin around umbilicus for discoloration.
    May appear red in color with intra-abdominal hemorrhage.
  • Look at feet and prepuce/vulva for ethylene glycol with Wood's Lamp.

Abdominal examination

  • Abdominal examination consists of 4 parts:
    • Visual inspection.
    • Auscultation.
    • Percussion.
    • Ballottement/palpation.

Visual inspection

  • Distention (hemoabdomen, mass effect).
  • Deformity (mass effect, ascites).
  • Bruising on skin.
  • Discoloration around umbilicus (indicative of intraabdominal hemorrhage).
  • Penetrating wounds.
  • Look at penis for discoloration, sand or grit, suggesting urethral obstruction Urethra: obstruction .


  • Increased borborygmi if acute obstruction, gastroenteritis, toxin.
  • Decreased borborygmi if chronic obstruction, anorexia, peritonitis, ileus.


  • Hyperresonant with intraabdominal air.
  • Hyporesonant if intraabdominal fluid.


  • Masses.
  • Organomegaly Abdominal organomegaly. Discrepancy in renal size is often seen in cats with ureteric obstruction.
  • Plication of intestines (linear foreign body).
  • Thickened intestines (FIP, lymphoma, parasites, inflammatory bowel disease).
  • Fluid (FIP, hepatic failure, right sided cardiac disease).
  • Large, firm urinary bladder  Feline lower urinary tract disease (FLUTD), Urethra: obstruction.
  • Distention.
  • Pain? Localized versus generalized?
  • Rectal examination (always look at both ends, may be difficult in smaller cats). Feel for:
    • Masses.
    • Sublumbar lymph nodes.
    • Urethra.
    • Feces.
    • Hematochezia.
    • Melena.
    • Obstipation.
  • Look at penis for discoloration, sand or grit, indicating urethral obstruction.
  • Look at rectum externally for string/foreign body.

Diagnostic Investigation

First wave diagnostics

Always perform abdominal radiographs before performing abdominocentesis, as iatrogenic pneumoperitoneum can occur during procedure.

  • Masses, organ displacement.
  • Organomegaly Abdominal organomegaly.
  • Obstruction Intestine: foreign body - linear  Abdomen: foreign body - radiograph lateral    Abdomen: foreign body - radiograph VD .
    • Intestinal neoplasia (adenocarcinoma, lymphoma).
    • Intestinal granulomas (FIP associated).
    • Trichobezoar.
  • Plication of intestines (linear foreign body).
  • Foreign bodies.
  • Diaphragmatic hernia.
  • Calculi (renal, ureteral, cystic, urethral).
  • Intussusception Intussusception.
  • Partial or complete obstructions may require contrast radiography.
    • Barium sulfate indicated unless suspect gastrointestinal perforation.
    • Iodinated material if bowel perforation suspected.
  • Contraindications to performing abdominal radiographs:
    • Evisceration.
    • Post-operative with peritonitis.
    • Penetrating trauma.
    • Any respiratory difficulty.

Abdominal ultrasound

  • Masses.
  • Free fluid.
  • Architecture and size of abdominal organs.

Abdominal ultrasound/AFAST scan Triage (Abdominal focused asssesement using sonography for trauma)

  • Free fluid.
  • Masses.
  • Architecture and size of abdominal organs.
  • Ultrasound guided abdominocentesis.

Abdominocentesis  Abdominocentesis

  • Indications:
    • Loss of serosal detail on abdominal radiographs.
    • Penetrating injury, where penetration reaching the peritoneal cavity is unclear.
    • Persistent abdominal pain of unknown cause.
    • Post-operative complications following abdominal surgery.
    • Perform four quadrant abdominocentesis or ultrasound guided abdominocentesis.

Diagnostic peritoneal lavage

  • Indicated when peritonitis or other effusive disease is suspected but other techniques have failed to provide a diagnostic sample Peritoneal fluid: analysis.

Fluid analysis

See table 'Assessment of diagnostic peritoneal lavage fluid'  Assessment of diagnostic peritoneal lavage fluid  .



Standard Treatment

Procedural diagnosis

  • Make decision based on:
    • Initial clinical signs.
    • Results of initial evaluation.
    • Response to initial therapy.

Definitive clinicopathologic diagnosis

  • More accurate.
  • Directs you at treating CAUSE, not just clinical signs.

Initial Stabilization

See table 'Analgesics for treating acute abdomen'  Analgesics for treating acute abdomen  .


  • Perfusion parameters:
  • Heart rate.
  • Capillary refill time.
  • Blood pressure.
  • Mucous membrane color.
  • Urine output.

Subsequent Management


Non-surgical causes of acute abdomen

Indications for surgery

  • Uncontrollable hemorrhage and inability to stabilize patient.
  • Free gas on plain abdominal radiographs.
  • Intracellular bacteria, fecal or vegetable/fiber material on DPL.
  • Greater than 2000 cells/mm3 on DPL.
  • Predominantly toxic neutrophils on DPL.
  • Bilirubin in abdominal fluid or green abdominal fluid.
  • Complete bowel obstruction or linear foreign body.
  • Ureteric obstruction.
  • Penetrating trauma/foreign body.
  • Gunshot wound to abdomen.
  • Evisceration.
  • Abdominal impalement.


Further Reading


Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Walters J M (2003) Abdominal paracentesis and diagnostic peritoneal lavage. Clin Tech Small Anim Pract 18 (1), 32-38 PubMed.

Other sources of information

  • Boag A & Huges D (2008) Emergency management of the acute abdomen in dogs and cats. 1. Investigation and initial stabilisation. In Practice 26 (9), 476-83 VetMedResource.
  • Mann F A (2000) Acute Abdomen: Evaluation an Emergency Treatment. Current Veterinary Therapy XIII. Ed J D Bonagura. WB Saunders Company, Philadelphia. pp160-164.
  • Holt D & Brown D (1999) Acute abdomen and gastrointestinal emergencies. In: Manual of Canine and Feline Emergency and Critical Care. Eds L G King and R Hammond R. British Small Animal Veterinary Association, United Kingdom. pp. 127-144.
  • Kleine L J (1997) Radiology of acute abdominal disorders of the dog and cat (Parts I and II). In: Emergency Medicine in Small Animal Practice: The Compendium Collection. Veterinary Learning Systems, Trenton, NJ. pp. 336-351.

Other Sources of Information