Hemoabdomen & Hemoperitoneum: Abdominal Bleeding in Cats

Overview of Abdominal Bleeding in Cats

Hemoperitoneum (also commonly called hemoabdomen) is defined as blood within the cat’s peritoneal (abdominal) cavity. It occurs following intra-abdominal hemorrhage as blood accumulates in the space between the abdominal wall and the abdominal organs.

Some causes of hemoperitoneum in cats include:

• Traumatic injury – the most common cause of hemoperitoneum.
• Intra-abdominal tumors – may rupture, bleed slowly, or invade into a blood vessel, causing blood to accumulate in the abdomen.
• Hematomas – organized, local collections of blood that can rupture and bleed.
• Coagulopathies – clotting disorders that can cause bleeding within the abdomen as well (as in other sites).

Depending on the rapidity and extent of the blood loss, hemoperitoneum may be an emergency situation.

Signs to Watch For

• Weakness
• Collapse
• Abdominal distension
• Bruising under the skin
• Increased respiratory efforts
• Pale mucus membranes (the best place to check is the inner lining of the lips and gums)

Other signs that might indicate more gradual blood loss include: anorexia, lethargy, intermittent weakness, and weight loss.

Diagnostic Tests for Hemoabdomen & Hemoperitoneum in Cats

A thorough history and physical exam is critical for prompt and accurate diagnosis. Your veterinarian may also recommend:

• Abdominal X-rays
• Abdominocentesis – inserting a needle and syringe into the abdominal cavity to obtain a fluid sample for diagnostic evaluation
• Analysis of the retrieved sample for evaluation
• Complete blood count

Depending on your pet’s condition and initial test results, additional testing may be required. Such testing may include:

• Biochemistry profile
• Coagulation panel
• Abdominal ultrasound
• Computed tomography (CT) or magnetic resonance imaging (MRI)

Treatment of Hemoabdomen & Hemoperitoneum in Cats

The general approach to treatment varies on the clinical condition of the patient and the cause of the hemoperitoneum. Therapy may include:

• Abdominocentesis (if pressure on the diaphragm is impeding respiration)
• Intravenous fluid therapy
• Blood transfusion
• Belly wrap
• Oxygen therapy
• Analgesic therapy (pain medication)
• Vitamin K administration
• Emergency exploratory surgery

Home Care

Hemoperitoneum may be an emergency situation. Veterinary care should be sought as soon as possible. Keep your pet calm, comfortable and warm. Minimize stress until you can get to a veterinary hospital. If a traumatic injury is suspected, be careful moving your pet as spinal injury or fractures may be present.

In-Depth Information on Hemoabdomen & Hemoperitoneum in Cats

Hemoperitoneum is a potentially life-threatening situation. The peritoneal or abdominal cavity is potentially a large space that can contain a significant volume of blood. If a large amount of blood is lost into this space, the abdominal musculature is stretched and abdominal distension becomes evident. Abdominal distension may cause discomfort or pain, leading to agitation and stress. Severe hemoperitoneum may cause pressure on the diaphragm, which may impede breathing.

Rapid blood loss into the abdomen may lead to a decrease in blood pressure and tissue perfusion: This can cause shock. As blood continues to be lost, the decrease in circulating red blood cells results in anemia. Pale mucus membranes are often seen. If veterinary care is not immediately available, rapid blood loss may cause death. Slower blood loss is more common, allowing owners more time to seek veterinary attention.

Chronic (long standing) or intermittent blood loss usually occurs more slowly and more subtle clinical signs are present. If the blood loss is slow, the body can reabsorb (auto transfuse) some of the free blood in the abdomen. Thus, animals may only have a small amount of blood in the abdominal cavity at any one time. Such animals may not present as an emergency, but they still have a serious underlying disease process. In these cases, appreciating the existence of hemoperitoneum is critical for proper case management.

If the cat has normal clotting parameters, bleeding into the abdomen will oftentimes stop on its own. Blood clots form that stop the bleeding. Sometimes, cats collapse because of acute blood loss, and then spontaneously recover because of the body’s compensatory mechanisms. These animals may appear pale and weak initially but slowly become stronger and their mucus membranes become pinker. Owners may describe intermittent episodes of weakness followed by spontaneous recovery. However, blood clots can become dislodged, especially with increased movement or manipulations. If blood clots are dislodged, the bleeding may start again. In many cases of hemoperitoneum caused by abdominal trauma, bleeding stops on its own.

Causes of Hemoabdomen & Hemoperitoneum in Cats

There are several causes of a hemoperitoneum. Probably the most common cause is trauma. A lacerated blood vessel within the abdomen or on the surface of an internal organ trauma may lead to rapid or slow bleeding, depending on the extent of organ or tissue damage. Outdoor cats are at significantly greater risk of hemoperitoneum than indoor cats. Younger cats are more likely to be traumatized and thus develop hemoperitoneum than older cats.

In young animals with a hemoperitoneum and no history of trauma, coagulopathy (bleeding disorder) should be suspected. In cats with a coagulopathy, bleeding into the peritoneum does not usually stop unless vitamin K or other therapy is initiated.

In older cats with a hemoperitoneum and no history of trauma, a bleeding abdominal tumor is often the cause. Bleeding tumors may cause rapid or chronic intermittent blood loss.

Specific causes of hemoperitoneum include:

• Trauma. The most common traumatic injury causing a hemoperitoneum occurs when a car has hit an animal. Severe abdominal trauma may cause a rapid death if the blood loss is profound. Most of the time, bleeding occurs more slowly and there is time to seek veterinary care. The spleen and liver are the internal organs most commonly traumatized, leading to hemoperitoneum. Less commonly, the bladder or kidneys may hemorrhage into the abdomen, but such injury is usually also associated with uroabdomen (urine within the peritoneal cavity). The bleeding that occurs may be mild or severe, but in most cases will stop without intervention. Other causes of trauma include gunshot and knife wounds.
• Tumors. Tumors of the abdomen may erode a blood vessel or simply rupture, causing an acute bleed. Tumors located in the body wall or associated with abdominal organs may cause bleeding into the abdomen. The most common tumor to cause intra-abdominal bleeding is a hemangiosarcoma (a tumor of blood vessels). These tumors are aggressive and malignant and are commonly found on the spleen or liver. Hemangioma is the benign form, but it is not as commonly seen. Hemangiosarcoma is a very common tumor in dogs, though it is rare in cats. In cats, abdominal tumors usually involve the spleen, mesentery, liver, or gastrointestinal tract.
• Hematomas. Hematomas are formed by broken blood vessels that cause blood to accumulate in a tissue or organ. They are a common cause of hemoperitoneum and are often associated with the spleen. Hematomas may be caused by previous trauma or more commonly nodular regeneration (excessive production of splenic tissue). Hematomas may be quite large and are indistinguishable from hemangiosarcomas at surgery.
• Coagulopathies. Rodenticide poisoning with products containing anticoagulants is a common cause of bleeding disorders in animals. The bleeding may be exclusively within the abdomen or may involve other sites (e.g. under the skin). Products containing the following active ingredients may cause a hemoperitoneum: warfarin, fumarin, chlorophacinone, diphacinone, pindone, bromadiolone, or brodaficoum.

Diagnosis In-depth

• Abdominal X-rays – A good test to see if fluid is present within the abdominal cavity. Although radiographs can confirm a diagnosis of fluid in the abdomen, they cannot determine the type of fluid present. Abdominal X-rays may also identify masses or lesions (e.g. tumors or hematomas). Unfortunately, a large volume of fluid in the abdomen often makes the radiographic visualization of masses more difficult.​
• The order of diagnostic tests depends on the clinical condition of the cat. In an emergency situation, the cat would be stabilized prior to any extensive diagnostic procedures. A rapid but thorough veterinary evaluation is critical to prioritizing appropriate diagnostic procedures.
• Abdominocentesis – A small sample of fluid is withdrawn from the abdominal cavity and the fluid is submitted for microscopic analysis. The bloody fluid withdrawn should not clot, since blood in the peritoneal space rapidly loses its ability to clot. When a hemorrhagic (bloody) fluid is obtained that does clot, it usually means that blood was inadvertently drawn from an abdominal blood vessel. Fluid analysis shows mainly red blood cells and white blood cells in quantities similar to those in peripheral blood. The hematocrit (red cell count) should be similar to that of the peripheral blood.
• Complete blood count – The CBC is an important test since it evaluates red and white blood cell numbers and morphology (shape/type). When a hemoperitoneum is suspected, a hematocrit is used to evaluate the degree of blood loss (anemia). The CBC also provides information on whether the bleeding is acute or chronic. Red blood cell morphology (shape) changes may suggest that hemangiosarcoma or other malignancy is present.
• Biochemical profile – A useful test to evaluate whether organ systems are affected. Animals with traumatic injuries (and sometimes, cancer) often have elevated liver enzymes. Kidney function may also be evaluated.
• Blood clotting tests – Important especially in young cats with no trauma history. If trauma and tumors within the abdominal cavity are ruled out, or if the bleeding has not stopping, a clotting panel is indicated.
• Abdominal ultrasound – Used to determine if there is an abdominal tumor or hematoma present. Unlike radiographs, fluid in the abdomen does not inhibit visualization of masses. An ultrasound-guided biopsy may be considered if a mass is found. Care must be taken when masses are biopsied as they tend to bleed. Splenic masses are most likely to present this problem.
• CT or MRI – Rarely, a mass is too small to be visualized on ultrasound. A CT or MRI, available at specialty hospitals, may identify these difficult-to-visualize masses.

Treatment In-depth

Your veterinarian may recommend one or more of the diagnostic tests described above. In the meantime, treatment of patient is required, especially if the problem is severe. The following nonspecific (symptomatic) treatments may be applicable to some, but not all, cats with hemoperitoneum. These treatments may reduce severity of clinical signs and provide relief for your pet. However, nonspecific therapy is not a substitute for treatment of the underlying disease causing your cat’s condition.

If possible, seek immediate veterinary care. A hemoperitoneum may be a life-threatening condition requiring immediate intervention.

• Intravenous fluids are given if extensive blood loss is suspected. Intravenous fluids maintain blood pressure and improve tissue perfusion. Following trauma and when bleeding abdominal masses are present, affected cats are commonly in shock and may have multiple organ failure. Fluid therapy is critical in these patients. Treated cats often respond dramatically to treatment.
• Blood transfusions may also be required if there is a significant blood loss causing anemia. Blood loss may be only within the abdomen, or it may be elsewhere in the body as well.
• A belly wrap is a pressure bandage placed around an animal’s abdomen. It causes an increased intra-abdominal pressure that sometimes slows or stops abdominal bleeding.
• Oxygen therapy may be needed in animals that have lost a large volume of blood. It is especially useful early in treatment while fluids or blood products are being administered. Oxygen is administered via oxygen cage, mask, or nasal canula.
• Analgesic medication – Keeping patients still and calm is important. Cats that are in pain have increased stress, flail around, and are more likely to re-injure themselves. Bleeding that stopped previously may start again. Treatment with narcotics, or other pain medications, helps keep affected cats more comfortable and more stable.
• Vitamin K is sometimes given if anticoagulant intoxication is suspected, even prior to getting test results back. The treatment has few side effects and rapid therapy improves prognosis.
• Exploratory surgery – If there is an abdominal mass, exploratory surgery may be the only way to obtain a diagnosis and properly treat the condition. If the clotting panel is normal and abdominal bleeding continues, an exploratory laparotomy is indicated to surgically stem the bleeding and find the cause of the problem.