Peritonitis - Cats and Dogs

Description

Peritonitis is defined as the inflammation of the peritoneum, which can be septic or non-septic. Septic peritonitis results from free bacteria in the peritoneal cavity, caused by perforating injuries to the gastrointestnal tract due to foreign bodies, necrosis secondary to obstruction or intussusception. Non-septic, also known as chemical peritonitis, may be the result of leakage of bile, urine or pancreatic enzymes. However, non-septic peritonitis can cause septic peritonitis, for example cases where septic urine is present.

Peritonitis is a multifactorial disease and the consequence if fatal in most cases.

Diagnosis

Clinical Signs

• Depressed
• Tachycardia
• Tachypnoea
• Pale, cyanotic or muddly mucous membranes
• Hypothermia or hyperthermia
• Abdominal pain

Laboratory Tests

Haematology

• Significant leucocytosis or leucopaenia

Biochemistry

• Hypoglycaemia
• Increased lactate concentration

Diagnostic Imaging

Radiography

• Abdominal radiography may reveal free gas in the abdomen. This is highly suggestive of peritonitis
• Thoracic radiograph should be assessed for signs of metastatic disease.

Histopathology

• Abdominal fluid collected for laboartory analysis via abdominocentesis. The fluid should be stained for intracellular bacteria and assessed for:
  • amylase and lipase for pancreatitis
  • bile for biliary leak
  • creatinine for urine
  • glucose (<2.8 mmol/l) and lactate (>5.5 mmol/l) for sepsis

Treatment

It is vital to identify cases which require emergency surgical intervention. Any of the following is a major indication:

• positive for intracellular bacteria.
• free gas visible in the abdominal radiograph.
• presence of penetrating injuries in the abdomen.

Fluid therapy

• Aggressive fluid therapy with crystalloid and colloid should be given on initial presentation to improve haemodynamic parameter.
• Fluid therapy is also very important in the postoperative period. Both crystalloid and colloid should be continued until the the patient is normotensive. However, if hypotension continues, a vasopressor such as vasopressin should be considered.

Analgesia

• Opiods should be given.

Antimicrobial

• Broad spectrum antibiotics should be given, preferably following culture and sensitivity test.

Prognosis

Guarded. A rapid diagnosis and treatment improves the prognosis.

References

• Ettinger, S.J. and Feldman, E. C. (2000) Textbook of Veterinary Internal Medicine Diseases of the Dog and Cat Volume 2 (Fifth Edition) W.B. Saunders Company.
• Hall, E.J, Simpson, J.W. and Williams, D.A. (2005) BSAVA Manual of Canine and Feline Gastroenterology (2nd Edition) BSAVA
• Nelson, R.W. and Couto, C.G. (2009) Small Animal Internal Medicine (Fourth Edition) Mosby Elsevier.