Home » Diseases » In dogs » Peritonitis (Inflammation of the Peritoneum)

Peritonitis (Inflammation of the Peritoneum) in Dogs

Occurrence: common
Location of illness: Abdomen/pelvis

Author: Dr. med. vet. Gisa Löwe | Last modified: 06.11.2025

Peritonitis, also known as inflammation of the peritoneumThe peritoneum is a thin membrane that covers the inner surface of the abdominal cavity and the outer surface of most abdominal organs. It plays an important role in immune defense and fluid regulation in the abdominal cavity., is a serious inflammation of the peritoneumThe peritoneum is a thin membrane that covers the inner surface of the abdominal cavity and the outer surface of most abdominal organs. It plays an important role in immune defense and fluid regulation in the abdominal cavity., the thin layer of tissue that lines the abdominalThe term "abdominal" refers to anything that concerns the belly or the abdomen. It is an adjectival expression used to describe the location, symptoms, or conditions that occur in the abdominal area. cavity and surrounds the abdominalThe term "abdominal" refers to anything that concerns the belly or the abdomen. It is an adjectival expression used to describe the location, symptoms, or conditions that occur in the abdominal area. organs.

The most important facts at a glance

Peritonitis in dogs is an inflammation of the peritoneumThe peritoneum is a thin membrane that covers the inner surface of the abdominal cavity and the outer surface of most abdominal organs. It plays an important role in immune defense and fluid regulation in the abdominal cavity., a sensitive membrane that surrounds the organs in the abdominalThe term "abdominal" refers to anything that concerns the belly or the abdomen. It is an adjectival expression used to describe the location, symptoms, or conditions that occur in the abdominal area. cavity. This condition can be caused by bacterial infections resulting from injuries, surgeries, or infections in other areas of the body. Non-infectious causes include leakage of gastric acid, bile, or pancreatic enzymesEnzymes are biological catalysts that accelerate specific chemical reactions in the body without being consumed. They play a crucial role in virtually all physiological processes. due to conditions such as pancreatitis or organ ruptures. Symptoms include abdominalThe term "abdominal" refers to anything that concerns the belly or the abdomen. It is an adjectival expression used to describe the location, symptoms, or conditions that occur in the abdominal area. pain, Vomiting, DiarrheaDiarrhea refers to the condition of frequent, watery bowel movements, which can be a sign of infections, digestive disorders, or other health problems., loss of appetite, and Fever. DiagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. involves a clinical examination, blood tests to check for inflammatory markers, and imaging techniques such as ultrasoundUltrasound refers to sound waves that are above the hearing threshold of the human ear. In medicine, ultrasound is used for diagnostic imaging procedures to visualize internal organs, tissues, and blood flow. or X-rays. An abdominalThe term "abdominal" refers to anything that concerns the belly or the abdomen. It is an adjectival expression used to describe the location, symptoms, or conditions that occur in the abdominal area. tap can help determine the type of inflammation.

Treatment often requires immediate medical intervention, including fluid therapyTherapy refers to the treatment of diseases or disorders with the aim of alleviating symptoms, promoting healing, or improving quality of life. Therapies can be medicinal, surgical, or through other medical interventions. and antibiotics to combat infections. In severe cases, surgery may be necessary to correct the cause of the inflammation. Intensive care after surgery is crucial for recovery. The prognosisThe prognosis is the prediction of the likely course and outcome of a disease based on the general state of health, the nature of the disease, and the response to treatment. It can provide information on how a disease is expected to develop. depends on the cause of the peritonitis and the speed of treatment; rapid diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. improves the chances of survival. Preventive measures include avoiding injuries, good hygiene standards, and regular veterinary examinations. Research focuses on better diagnostic and treatment methods as well as preventive measures.

Causes

The peritoneumThe peritoneum is a thin membrane that covers the inner surface of the abdominal cavity and the outer surface of most abdominal organs. It plays an important role in immune defense and fluid regulation in the abdominal cavity. is a sensitive membrane that forms a protective barrier and supports the organs in the abdominalThe term "abdominal" refers to anything that concerns the belly or the abdomen. It is an adjectival expression used to describe the location, symptoms, or conditions that occur in the abdominal area. cavity. It produces a small amount of fluid to ensure the organs can glide smoothly. In peritonitis, this membrane becomes inflamed, which can lead to an accumulation of fluid and other substances that impair the function of the abdominalThe term "abdominal" refers to anything that concerns the belly or the abdomen. It is an adjectival expression used to describe the location, symptoms, or conditions that occur in the abdominal area. organs.

The causes of peritonitis in dogs can be varied. One of the most common causes is a bacterial infectionAn infection is the colonization and multiplication of pathogens such as bacteria, viruses, fungi, or parasites in an organism, which often, but not always, leads to a disease., which can result from an injury to the abdominalThe term "abdominal" refers to anything that concerns the belly or the abdomen. It is an adjectival expression used to describe the location, symptoms, or conditions that occur in the abdominal area. cavity, a perforationA perforation is a rupture or hole in the wall of a hollow organ, such as the gastrointestinal tract or bladder, which can lead to the release of contents into the body and severe infection. Perforations are Emergencies that require rapid veterinary intervention in dogs and cats. of the gastrointestinalGastrointestinal refers to the gastrointestinal tract, a system that extends from the oral cavity to the anus and is responsible for the digestion of food and the absorption of nutrients. tract, or the migrationMigration refers to the movement or migration of cells or organisms from one place to another. In veterinary medicine, this can include the movement of parasites within the body of dogs and cats. of bacteriaBacteria are microscopic, single-celled organisms that exist in almost every environment on Earth. Some types of bacteria are beneficial or even essential to life, while others can cause disease. from other infected areas of the body. This also includes complications following surgery or traumaA trauma refers to a physical injury or damage caused by external force. Traumas can range from simple cuts to severe multiple injuries. such as bite Wounds or car accidents.

Another cause can be a non-infectious irritation of the peritoneumThe peritoneum is a thin membrane that covers the inner surface of the abdominal cavity and the outer surface of most abdominal organs. It plays an important role in immune defense and fluid regulation in the abdominal cavity., caused by the leakage of gastric acid, bile, or pancreatic enzymesEnzymes are biological catalysts that accelerate specific chemical reactions in the body without being consumed. They play a crucial role in virtually all physiological processes.. These can be caused by conditions such as pancreatitis, gallbladder ruptureA rupture is a tear or break in an organ or tissue. It can be caused by trauma, illness, or overextension, and often requires medical intervention., or gastric perforationA perforation is a rupture or hole in the wall of a hollow organ, such as the gastrointestinal tract or bladder, which can lead to the release of contents into the body and severe infection. Perforations are Emergencies that require rapid veterinary intervention in dogs and cats.. Systemic diseases such as liver or kidney failureRenal failure is a condition in which the kidneys can no longer adequately perform their function of filtering and excreting waste products from the blood. It can be acute or chronic and requires immediate medical treatment. can also promote peritonitis.

Symptoms

Very common symptoms:

Common symptoms:

Rare symptoms:

Pale Mucous Membranes

The symptoms of peritonitis in dogs are often severe and require immediate veterinary treatment. The most common signs include severe abdominalThe term “abdominal” refers to anything that concerns the belly or the abdomen. It is an adjectival expression used to describe the location, symptoms, or conditions that occur in the abdominal area. pain, which can be manifested by defensive reactions to the touch or a stiff gait. The dog may also show signs of general weakness, loss of appetite, and Vomiting.

Fever is another common symptom that indicates an infectionAn infection is the colonization and multiplication of pathogens such as bacteria, viruses, fungi, or parasites in an organism, which often, but not always, leads to a disease.. In some cases, the dog may also have an accelerated breathing or heart rate. A bloated abdomenThe abdomen, also known as the abdominal cavity, is the part of the body located between the rib cage and the pelvis. It houses several important organs, including the stomach, liver, kidneys, intestines, and spleen., dehydrationDehydration occurs when the body loses more fluid than it takes in. This can lead to a number of problems, including headaches, Dizziness, and in extreme cases, renal failure or Cardiovascular collapse., and a rapid drop in blood pressure can also occur, indicating a worsening of the condition.

In severe cases, sepsis, a life-threatening reaction to an infectionAn infection is the colonization and multiplication of pathogens such as bacteria, viruses, fungi, or parasites in an organism, which often, but not always, leads to a disease., can occur, which can lead to shock and organ failure. Rapid recognition and treatment of symptoms is crucial for the survival chances of the affected dog.

Diagnosis

The diagnosis of peritonitis begins with a thorough clinical examination of the dog by a veterinarian, who will look for signs of abdominalThe term "abdominal" refers to anything that concerns the belly or the abdomen. It is an adjectival expression used to describe the location, symptoms, or conditions that occur in the abdominal area. pain and other symptoms. A medical historyThe medical history is the systematic collection of a patient's medical history through questioning. It includes information about previous illnesses, treatments, allergies, and lifestyle habits., including information about possible pre-existing conditions, injuries, or surgeries, can also be helpful.

Blood tests are an important part of the diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. to check for inflammatory markers, infections, and the dog’s general health. An elevated white blood cell count may indicate an infection.

Imaging procedures such as X-rays or ultrasoundUltrasound refers to sound waves that are above the hearing threshold of the human ear. In medicine, ultrasound is used for diagnostic imaging procedures to visualize internal organs, tissues, and blood flow. can be used to detect fluid accumulation, air in the abdominalThe term "abdominal" refers to anything that concerns the belly or the abdomen. It is an adjectival expression used to describe the location, symptoms, or conditions that occur in the abdominal area. cavity, or other abnormalities. In some cases, a diagnostic abdominalThe term "abdominal" refers to anything that concerns the belly or the abdomen. It is an adjectival expression used to describe the location, symptoms, or conditions that occur in the abdominal area. tap may be performed, in which a sample of abdominalThe term "abdominal" refers to anything that concerns the belly or the abdomen. It is an adjectival expression used to describe the location, symptoms, or conditions that occur in the abdominal area. fluid is taken to identify the type of inflammation and possible pathogens.

Therapy

Treatment of peritonitis usually requires immediate and aggressive medical intervention. An important first step is stabilizing the dog, which may include fluid therapyTherapy refers to the treatment of diseases or disorders with the aim of alleviating symptoms, promoting healing, or improving quality of life. Therapies can be medicinal, surgical, or through other medical interventions. to correct dehydrationDehydration occurs when the body loses more fluid than it takes in. This can lead to a number of problems, including headaches, Dizziness, and in extreme cases, renal failure or Cardiovascular collapse. and electrolyte imbalances.

Antibiotics are often necessary to combat bacterial infections. The choice of antibiotic depends on the type of bacteria involved in the infectionAn infection is the colonization and multiplication of pathogens such as bacteria, viruses, fungi, or parasites in an organism, which often, but not always, leads to a disease. and can be adjusted after culture and sensitivity testing.

In many cases, surgery is required to correct the cause of the peritonitis, such as a perforationA perforation is a rupture or hole in the wall of a hollow organ, such as the gastrointestinal tract or bladder, which can lead to the release of contents into the body and severe infection. Perforations are Emergencies that require rapid veterinary intervention in dogs and cats. of the gastrointestinalGastrointestinal refers to the gastrointestinal tract, a system that extends from the oral cavity to the anus and is responsible for the digestion of food and the absorption of nutrients. tract or a ruptured organ. During the operation, the abdominalThe term "abdominal" refers to anything that concerns the belly or the abdomen. It is an adjectival expression used to describe the location, symptoms, or conditions that occur in the abdominal area. cavity is usually rinsed to remove pus and other infectiousInfectious describes the ability of a pathogen to be transmitted from one individual to another and trigger an infection. It also refers to diseases caused by such pathogens. materials.

After surgery, the dog requires intensive care, including pain management and ongoing monitoring. Depending on the severity of the condition, several days of inpatient treatment may be necessary.

Prognosis and follow-up care

The prognosis for dogs with peritonitis depends on the cause of the inflammation, the dog’s general health, and the speed of treatment. Early diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. and treatment significantly improve the chances of survival.

With untreated peritonitis or complications such as sepsisSepsis is a life-threatening condition caused by the body's overwhelming response to an infection, which can lead to damage to its own tissues and organ failure., the prognosisThe prognosis is the prediction of the likely course and outcome of a disease based on the general state of health, the nature of the disease, and the response to treatment. It can provide information on how a disease is expected to develop. is often poor. Even with extensive surgical procedures, recovery can be lengthy, and there is a risk of postoperativePostoperative refers to the time after a surgical operation. This phase includes recovery and the management of possible complications after the procedure. complications.

Dogs recovering from peritonitis may require long-term follow-up care to prevent relapses and improve overall health.

Prevention

The prevention of peritonitis in dogs includes measures to avoid injuries and infections. This includes ensuring that the dog is kept in a safe environment to avoid traumaA trauma refers to a physical injury or damage caused by external force. Traumas can range from simple cuts to severe multiple injuries. and adhering to good hygiene standards, especially after surgery or with existing Wounds.

Regular veterinary examinations can help detect and treat underlying conditions early before they lead to peritonitis. Observing the dog for early signs of abdominalThe term "abdominal" refers to anything that concerns the belly or the abdomen. It is an adjectival expression used to describe the location, symptoms, or conditions that occur in the abdominal area. discomfort and consulting a veterinarian in a timely manner can also help avoid serious complications.

A balanced diet and adequate hydration support the dog’s general health and strengthen its immune systemThe immune system is the body's defense system against infectious agents such as bacteria, viruses, fungi, and parasites. It comprises a complex network of organs, cells, and molecules that work together to protect the body., which can reduce the risk of infections and related diseases.

Outlook on current research

Research on peritonitis in dogs focuses on various aspects of the disease, including its causes, diagnostic methods, and treatment options. Currently, much emphasis is placed on the development of advanced diagnostic techniques to detect the disease earlier and more accurately. One focus is on imaging techniques such as ultrasoundUltrasound refers to sound waves that are above the hearing threshold of the human ear. In medicine, ultrasound is used for diagnostic imaging procedures to visualize internal organs, tissues, and blood flow. and CT scans, which can help quickly identify fluid accumulation and inflammatory changes in the abdominalThe term "abdominal" refers to anything that concerns the belly or the abdomen. It is an adjectival expression used to describe the location, symptoms, or conditions that occur in the abdominal area. cavity.

Another significant area of research addresses the role of the immune systemThe immune system is the body's defense system against infectious agents such as bacteria, viruses, fungi, and parasites. It comprises a complex network of organs, cells, and molecules that work together to protect the body. in the development and progressionProgression refers to the advancement or worsening of a disease over time. It describes an increase in the severity or extent of the disease symptoms. of peritonitis. Researchers are investigating how the dog’s immune systemThe immune system is the body's defense system against infectious agents such as bacteria, viruses, fungi, and parasites. It comprises a complex network of organs, cells, and molecules that work together to protect the body. responds to infections or injuries in the abdominalThe term "abdominal" refers to anything that concerns the belly or the abdomen. It is an adjectival expression used to describe the location, symptoms, or conditions that occur in the abdominal area. cavity and how these responses might be modified to support recovery. The extent to which genetic factors might play a role in susceptibility to peritonitis is also being investigated.

In terms of treatment, intensive work is being done to develop new antibiotics and anti-inflammatory drugsAnti-inflammatory drugs are medications that reduce inflammation. They can be divided into nonsteroidal anti-inflammatory drugs (NSAIDs) and corticosteroids and are used in dogs and cats to reduce Inflammatory conditions and Pain. to improve treatment outcomes. Research into probiotic therapies is also underway to assess whether these can support intestinalIntestinal refers to the intestine, the part of the digestive tract that extends from the stomach to the anus. Intestinal diseases affect the small and/or large intestine. health and the immune systemThe immune system is the body's defense system against infectious agents such as bacteria, viruses, fungi, and parasites. It comprises a complex network of organs, cells, and molecules that work together to protect the body., thereby reducing the risk of peritonitis. At the same time, surgical techniques are being researched to improve the results of operations to correct the underlying causes of peritonitis.

In the long term, some studies aim to develop preventive measures that could reduce the risk of developing peritonitis in dogs. This includes both the investigation of nutritional factors and the improvement of general health monitoring, especially in dogs who are at higher risk due to pre-existing conditions or genetic predispositions.

The collaboration between veterinary physicians and scientists worldwide is a crucial factor for advances in peritonitis research. By sharing knowledge and resources, new insights are gained that should ultimately lead to better diagnostic and treatment approaches. It is expected that these efforts will lead to significant improvements in the care of dogs with peritonitis in the coming years.

Frequently asked questions (FAQs)

What is Peritonitis in Dogs? Peritonitis is an inflammation of the peritoneumThe peritoneum is a thin membrane that covers the inner surface of the abdominal cavity and the outer surface of most abdominal organs. It plays an important role in immune defense and fluid regulation in the abdominal cavity., the membrane that lines the abdominalThe term "abdominal" refers to anything that concerns the belly or the abdomen. It is an adjectival expression used to describe the location, symptoms, or conditions that occur in the abdominal area. cavity and surrounds the internal organs. It can be caused by infections, injuries, or other underlying conditions and often requires urgent veterinary treatment.
What symptoms does a dog with peritonitis show? The most common symptoms include abdominal pain, Fever, Vomiting, DiarrheaDiarrhea refers to the condition of frequent, watery bowel movements, which can be a sign of infections, digestive disorders, or other health problems., loss of appetite, and a bloated abdomenThe abdomen, also known as the abdominal cavity, is the part of the body located between the rib cage and the pelvis. It houses several important organs, including the stomach, liver, kidneys, intestines, and spleen.. The dog may also be lethargic and show signs of dehydrationDehydration occurs when the body loses more fluid than it takes in. This can lead to a number of problems, including headaches, Dizziness, and in extreme cases, renal failure or Cardiovascular collapse..
How is peritonitis diagnosed in dogs? The diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. is based on a combination of clinical symptoms, blood tests, imaging procedures such as ultrasoundUltrasound refers to sound waves that are above the hearing threshold of the human ear. In medicine, ultrasound is used for diagnostic imaging procedures to visualize internal organs, tissues, and blood flow. or X-rayX-ray is an imaging technique that uses X-rays to create images of the inside of the body. It is often used to diagnose bone fractures, lung diseases, and other conditions., and sometimes an abdominalThe term "abdominal" refers to anything that concerns the belly or the abdomen. It is an adjectival expression used to describe the location, symptoms, or conditions that occur in the abdominal area. tap to collect fluid for analysis.
What causes can peritonitis have in dogs? Common causes include bacterial infections, injuries to the abdominalThe term "abdominal" refers to anything that concerns the belly or the abdomen. It is an adjectival expression used to describe the location, symptoms, or conditions that occur in the abdominal area. wall, perforated gastrointestinalGastrointestinal refers to the gastrointestinal tract, a system that extends from the oral cavity to the anus and is responsible for the digestion of food and the absorption of nutrients. ulcers, pancreatitis, or complications after surgery.
How is peritonitis treated in dogs? Treatment depends on the cause but usually includes antibiotics to combat infections, pain relievers, intravenous fluid therapyTherapy refers to the treatment of diseases or disorders with the aim of alleviating symptoms, promoting healing, or improving quality of life. Therapies can be medicinal, surgical, or through other medical interventions. for rehydration, and sometimes surgical intervention to correct the underlying cause.
Is peritonitis curable in dogs? Yes, with timely and appropriate treatment, peritonitis can be cured. However, the prognosisThe prognosis is the prediction of the likely course and outcome of a disease based on the general state of health, the nature of the disease, and the response to treatment. It can provide information on how a disease is expected to develop. depends on the severity of the condition and the underlying cause.
Can all dog breeds get peritonitis? Yes, all dog breeds and mixes can get peritonitis, although certain genetic or health predispositions may increase the risk.
How can I reduce the risk of peritonitis in my dog? A balanced diet, regular veterinary check-ups, and avoiding injuries can help reduce the risk. If there are known risk factors, you should have your dog closely monitored.
Can peritonitis be fatal in dogs? Yes, without appropriate and rapid treatment, peritonitis can be life-threatening. It is important to seek veterinary attention immediately if you suspect this condition.
How quickly must a dog with suspected peritonitis be treated? A dog with suspected peritonitis should be treated by a veterinarian as soon as possible, as the condition can deteriorate rapidly. Early intervention is crucial for successful treatment.