Peritonitis in Dogs
Dr. Dawn Ruben
An abdominal tap. A needle and syringe are used to obtain a fluid sample. This sample is then analyzed for the presence of bacteria and certain cells, including white blood cells and red blood cells. The protein level can also be determined.
Various diagnostic techniques are used to diagnose peritonitis. These include:
Complete blood count. A complete blood count (CBC) can determine the number of white blood cells, red blood cells and platelets. In peritonitis, the white blood cell count is often elevated. The red blood cell count may be elevated if the animal is dehydrated.
Biochemical profile. A biochemical profile is performed to determine the function of the body's organs. Depending on the underlying cause of the peritonitis, various abnormalities may be present. The kidney and liver functions may be abnormal. The electrolytes, such as sodium, potassium and chloride may be low due to excessive vomiting. If the animal has developed an overwhelming body infection (sepsis), the blood sugar level may be low. Pancreatic enzymes, lipase and amylase, may be elevated if pancreatitis is present.
Culture. The abdominal fluid can be cultured to determine the type of bacteria present and which antibiotics are most effective.
X-rays. Abdominal X-rays are taken to determine if there is fluid present in the abdomen or if there are any tumors, masses or intestinal blockages.
Abdominal ultrasound can be performed to help confirm the presence of fluid and to help determine the underlying cause of the peritonitis. Abdominal ultrasound can help detect liver abscesses, pancreatitis, intestinal blockage or gall bladder rupture.
Peritonitis can be treated medically or surgically, depending on the underlying cause of the peritonitis. If peritonitis is mild, medical therapy may be sufficient. Prompt surgery should be performed in cases of moderate or severe peritonitis or if the gastrointestinal tract, urinary bladder or gall bladder is ruptured.
Medical therapy is crucial in correcting electrolyte abnormalities, controlling bacterial infections and controlling pain. Medical therapy includes:
Intravenous fluids or other types of fluids. If the protein level is low, hetastarch may be administered.
Antibiotics should be selected based on culture and sensitivity. While waiting for the results, a combination of an aminoglycoside and a penicillin or cephalosporin can be administered. A commonly used combination is gentamicin and cefazolin.
Pain can be treated by using morphine or similar drugs.
Surgery is recommended in cases of moderate to severe generalized peritonitis or if gastrointestinal, urinary bladder or bile duct rupture is suspected or confirmed.
Exploratory surgery is often the treatment of choice. This allows for exploration of the abdominal cavity to correct the underlying cause of the peritonitis. This may involve intestinal surgery, repair of a ruptured urinary bladder, abscess or mass removal or other surgical procedures.
After correction of the underlying cause, a feeding tube may be placed.
In addition, the abdomen is thoroughly lavaged with sterile saline solution.
Depending on the severity of contamination and the ability to remove all fluid and debris, the abdomen is either surgically closed or left open. If left open, the animal is hospitalized and the abdomen is bandaged. The bandage is changed often until there is minimal fluid. The incision is then closed. This may take several days before the abdomen can be closed and the animal sent home.
Antibiotics are often continued for 1 to 2 weeks. Pain control may also be needed for several days. Additional follow-up will depend on the underlying cause of the peritonitis and the animal's response to therapy.
Animals diagnosed and treated for peritonitis require close monitoring immediately after discharge from the hospital. A complete blood count and biochemical profile may be repeated until the values are within normal ranges.