Peritonitis in Dogs This article is verified by a vet

Peritonitis in Dogs

Abdominal pain may indicate peritonitis in dogs

Peritonitis in dogs is a serious condition that, if left untreated, can be fatal for the affected animal. Here’s what you need to know about what triggers peritonitis in dogs and how it’s treated.

How Dangerous is Peritonitis in Dogs?

Peritonitis is an inflammation of the peritoneum in dogs, a thin layer lining the space between the inner lining of the abdominal wall and the envelope of the abdominal organs, also known as the peritoneal cavity.

If the peritoneum is inflamed, it can have serious consequences for the surrounding organs and the health of your dog.

Therefore, veterinary treatment is crucial, especially for the septic form.

Warning: The Septic Form is an Emergency

Not all cases of peritonitis in dogs are severe. However, if it stems from an infection, it’s an instance of septic peritonitis and thus an emergency. Septic peritonitis can have dangerous health consequences, so you should visit a vet immediately if you suspect your dog has peritonitis.

peritonitis symptoms © JM Soedher / stock.adobe.com
If your dog assumes the so-called praying position, this could indicate an upset stomach.

Symptoms: What are the Signs of Peritonitis in Dogs?

What symptoms your dog shows as a result of peritonitis varies greatly depending on the cause and form of the condition. Initially, dogs with peritonitis exhibit only unspecific symptoms.

As the disease progresses, more specific symptoms, indicative of peritonitis, may arise, such as:

  • poor general condition
  • Fever
  • Abdominal pain, which can be indicated by the “prayer position”
  • Vomiting
  • Diarrhoea

When Should I Visit the Vet?

As soon as your dog shows signs of illness, it’s best to take it to a vet early on.

Note: A rapid and throbbing pulse and increased breathing rate are signs of a life-threatening shock condition. You should seek veterinary care for your dog without delay if these symptoms appear.

How Long Does Peritonitis in Dogs Last?

Peritonitis in dogs typically develops slowly at first and can last several weeks.

Diagnosis: How is Peritonitis in Dogs Detected?

To diagnose peritonitis in your dog, the vet will conduct various examination steps. They will first ask you detailed questions about the progression of symptoms and previous treatments and surgeries.

After a general examination, more steps will follow.

Palpation of the Abdominal Organs

If your dog has severe abdominal pain, its abdominal wall will typically be tense. However, in apathetic dogs, it’s sometimes possible to palpate the abdominal organs from the outside.

Based on the size, position, and texture, your vet may detect initial signs of peritonitis in your dog.

Imaging Techniques

To gather more clues about peritonitis, an X-ray or an ultrasound examination can be helpful.

A loss of detail in the abdomen is typical of peritonitis: organs aren’t as visible as they would be in a healthy dog due to increasing fluid accumulation leading to an effusion in the abdomen.

Abdominal Fluid Aspiration

Although an effusion can be identified on an X-ray, the quality of the fluid can’t be assessed. Therefore, the vet will extract a sample through abdominal fluid aspiration.

They will analyze the drawn fluid, with an effusion high in cell and protein content being typical of peritonitis in dogs.

Blood Testing

A blood test provides further information about potential causes and the severity of the peritonitis.

For instance, in severe cases of peritonitis, there is often an increase in white blood cells (leukocytosis) and neutrophils (neutrophils). Therapy: How is Peritonitis in Dogs Treated? Depending on the severity and form of the disease, treatment is a combination of supportive care and surgical intervention.

Therapy: How is Peritonitis in Dogs Treated?

Depending on the severity and form of the disease, treatment is a combination of supportive care and surgical intervention.

Supportive Treatment

Various remedies can help stabilize your dog’s circulation and relieve symptoms. These primarily include:

  • Intravenous fluid therapy and balancing of electrolyte shifts
  • Administering oxygen
  • Correcting acid-base balance, such as with bicarbonate
  • Usage of antibiotics (plus antibiogram) and pain relief
  • possibly using anti-nausea medication

Surgical Treatment

Septic peritonitis in dogs is always an emergency requiring immediate surgical intervention. A pre-condition for anaesthesia is that your dog is stable.

During the laparotomy, which is the opening of the abdominal cavity, the vet will look for and eliminate the cause of the disease.

They will also take samples for culturing bacteria and testing for possible resistance (antibiogram), remove dead and contaminated tissue, and flush the abdominal cavity.

After Surgery: Good Aftercare

Treatment doesn’t end with surgery. Post-operative care is crucial for successful therapy. Your dog will need more energy than before.

A feeding tube is often inserted during the operation. Patients usually stay at the clinic for several days post-operation for close health monitoring to ensure a smooth healing process.

Causes: How Does Peritonitis in Dogs Develop?

Peritonitis in dogs often follows a bacterial infection, although this is not always the case.

Therefore, vets categorise the disease into primary, caused through the blood, and secondary, originating internally.

Primary Peritonitis (Hematogenous)

Primary peritonitis is very rare in dogs. It occurs due to a spontaneous bacterial infection, for example, with Actinomyces, Clostridia, or Nocardia, combined with a weakened immune system.

Secondary Peritonitis (Endogenous)

Secondary peritonitis is more common in dogs. It arises due to an infection in the abdominal area or through invading pathogens as a result of an injury — which can occur if the abdominal wall is torn.

The secondary form is further classified into aseptic and septic forms:

  • Aseptic Peritonitis is a sterile inflammation caused by factors other than infections, such as chemical or physical disturbances to the peritoneum. Irritation can be due to medications, such as antibiotics, or foreign materials like leftover sutures, as well as tumours causing sterile inflammation.
  • Septic (Infection-related) Peritonitis is the more frequent type and often results from injuries to the gastrointestinal tract, allowing pathogens into the abdominal cavity. Typical causes include burst surgical wound edges or sharp foreign objects.

Prognosis: Can Peritonitis in Dogs be Cured?

Whether your dog survives peritonitis depends on many factors. The sooner you consult your vet, the better. However, in the case of septic peritonitis, the condition can be fatal. The mortality rate for this type is between 20 to 48 percent.

Prevention: Can Peritonitis in Dogs be Prevented?

It’s generally impossible to prevent peritonitis in dogs. Too many triggers are beyond control and can lead to the severe illness.

It’s all the more important to seek veterinary assistance at the first signs and to maintain good health for your dog.

This article from zooplus Magazine is purely informative. If your pet is experiencing discomfort, contact your veterinarian for diagnosis and treatment.

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Franziska G., Veterinarian
Profilbild von Tierärztin Franziska Gütgeman mit Hund

At the Justus-Liebig-University of Giessen I was extensively trained as a veterinarian and was able to gain experience in various fields such as small animal, large animal and exotic animal medicine as well as pharmacology, pathology and food hygiene. Since then, I have been working not only as a veterinary author, but also on my scientifically driven dissertation. My goal is to better protect animals from pathogenic bacterial organisms in the future. Besides my veterinary knowledge, I also share my own experiences as a happy dog owner and can thus understand and enlighten fears and problems as well as other important questions about animal health.


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