If internal bleeding is caused by trauma, often from being hit by a car, the bleeding may be profuse and occur rapidly. This is an emergency situation requiring immediate veterinary attention. The liver and spleen are the most commonly affected organs in a traumatic accident. Other life-threatening injuries may also be present after extreme trauma has happened. The abdominal cavity is very large and can contain a high volume of blood. The cat may go into shock from abdominal bleeding. 

Severe internal conditions can also cause internal bleeding, however, this bleeding tends to be slower. The body may also reabsorb some of the blood collected in the abdomen, making the bleeding appear to be less than it is. Gastrointestinal cancer can cause bowels to rupture, which can lead to slow internal bleeding. Ulcerations and hematomas can also contribute to chronic blood loss into the abdomen. These conditions, while not emergencies, are still severe and can be life-threatening. Veterinary assessment is required. 

The abdomen of a cat is a large cavity containing most of the vital organs in the body. The complete digestive tract is housed within the abdomen. Extreme injuries from trauma or progressed internal ailments can cause blood vessels within the abdomen to rupture and bleed into the space between organs. This is sometimes referred to as hemoperitoneum or hemoabdomen.

Depending on whether the abdominal bleeding is acute or chronic, varying symptoms may reveal the issue. In cases of extreme traumatic injuries, many other visible symptoms may be present. Do not hesitate to rush your cat to an animal hospital if you suspect it has been hit by a car. All symptoms to watch for are as follows:

Anything that causes the internal organs to rupture will lead to abdominal bleeding. This is almost always a serious ailment. Identifying the cause can lead to a more effective treatment plan. Common causes are listed below.

In the case of an emergency, rush your cat to the nearest animal hospital or veterinary clinic immediately. Exercise care when moving an injured cat, as spinal issues and broken bones may be made worse by manipulation. Once there, a veterinarian will fully examine your cat for all injuries present. This examination may reveal many injuries that will need to be addressed, starting with the most serious issue at hand. The main focus will be to find the area that is bleeding and limit or stop blood loss as soon as possible.

In cases of slower blood loss, many tests will need to be run to identify the underlying cause of abdominal bleeding. Your cat's medical history can be helpful in finding possible health problems. Full blood work will be needed, including a complete blood count. This can identify both anemia or malignancy within the cat. X-rays or ultrasounds may be used to show fluid, growths, hematomas or ulcers present in the abdomen. If masses are too small for ultrasound imaging to detect, an MRI or CT scan may be necessary. 

Abdominocentesis is often performed in instances of abdominal bleeding. This involves filling a syringe with the blood-filled fluid in the abdomen for microscopic evaluation and/or culture. If growths have been identified, a biopsy of growth tissue may be needed for a histopathological exam. A coagulation panel may also be deemed necessary. Feline leukemia virus should be tested for.

In both emergency and nonemergency settings, the bleeding must be stopped. There are various ways of doing this depending on the reason for the bleeding. 

Emergency Procedures 

These treatments are applied to cats suffering from major blood loss. The goal is to keep the cat alive and maintain stability so further surgeries can be performed. Intravenous fluids are often administered to keep fluid volumes up and increase blood pressure. Blood transfusions may be needed if too much blood has been lost. Oxygen can help a cat suffering from breathing difficulties due to excess fluid in the abdomen pushing on its lungs and a reduced population of oxygen carrying red blood cells. Vitamin K may be given as it enhances the body's ability to clot blood. A belly wrap may be put on the cat to compress the abdomen and temporally stop bleeding with pressure. Painkillers may be given to calm the cat.

In the case of trauma, often the only way to find the source of bleeding is to do so surgically. An exploratory laparotomy may be performed. The goal is to identify internal wounds and seal them if possible. This surgery carries many risks and is used only to help save a cat's life.

If cancerous or benign growths are found to be bleeding within the body, surgically removing these growths can stop internal bleeding. Success depends on the number and location of growths present. If cancer is residing in the body, radiation therapy or chemotherapy may need to be paired with surgery for optimum effectiveness.

If a bleeding ulcer is discovered, certain medications may be prescribed to lower stomach acidity within the cat. This allows the ulcer to heal without further damage occurring. These prescriptions usually last for six to eight weeks.

If the cat has survived surgery, proper postoperative care is needed. This involves keeping the incision site clean and limiting the cat’s activity during the healing process. Watch for any signs of infection and bring the cat back to the veterinarian immediately if signs begin to show. For severe internal injuries, the healing process can be slow. Confining your cat to a crate may be necessary during this time if injuries are extensive enough.

If a benign tumor has been removed successfully, generally the prognosis is good with a full recovery possible. Gastrointestinal cancer carries a worse prognosis due to its aggression and tendency to spread throughout the body. If the cat has experienced kidney or liver failure, it may not survive long. A cat who has suffered from ulcers should be put on a restricted, bland diet containing foods like chicken, rice, and cottage cheese. Keeping your cat indoors can greatly reduce incidents of trauma. Removing rodenticides from your home, and locking away any other anticoagulants, can help keep your cat safe from poisoning.