Seeing blood in your cat’s vomit, medically termed hematemesis, signals a serious underlying health issue. This symptom is never normal and requires immediate veterinary attention. Cats are masters at concealing illness, meaning that by the time blood is visible, the condition may be advanced. Prompt action and a rapid diagnosis are necessary to ensure the best possible outcome for your pet.
Identifying the Source and Appearance of Blood
The appearance of the blood provides the first important clue about its origin within the body. True hematemesis, which is bleeding from the stomach or upper small intestine, can manifest in two distinct ways. If the bleeding is fresh and rapid, the vomit will contain bright red blood or pink streaks, indicating the blood has not been exposed to stomach acid for long.
A more concerning presentation is vomit that looks dark, granular, and resembles coffee grounds. This texture is the result of hydrochloric acid in the stomach partially digesting the blood, a process that turns the hemoglobin dark brown or black. This “coffee grounds” appearance suggests a slower, ongoing bleed in the stomach or upper digestive tract.
True hematemesis must be distinguished from other sources of bleeding. Hemoptysis, blood originating from the lungs or airways, is typically frothy and expelled with a cough rather than the heaving motion of vomiting. Bleeding from the mouth, such as from severe dental disease or an oral injury, can also be swallowed and then vomited, confusing the source.
Potential Medical Causes of Vomiting Blood
The causes of hematemesis involve a breakdown of the protective lining of the gastrointestinal tract or a failure of the body’s clotting mechanisms. One common localized cause is severe gastritis, inflammation of the stomach lining that can lead to superficial erosions and bleeding. Gastrointestinal ulcers, which are deeper, open sores, can develop due to chronic inflammation, certain medications, or underlying tumors.
Foreign bodies are another frequent cause, particularly in younger or curious cats who ingest items like string, thread, or sharp fragments of bone or plastic. These objects can physically lacerate the delicate mucosal lining of the esophagus or stomach as they pass through, or they can cause severe inflammation and obstruction. Chronic conditions like Inflammatory Bowel Disease (IBD) can also lead to hematemesis when the persistent, severe inflammation damages the intestinal lining to the point of bleeding.
Beyond the digestive tract, systemic diseases can impair the body’s ability to stop bleeding, leading to blood loss into the GI tract. Severe kidney failure, for example, can cause uremic gastritis, where toxins that build up in the blood irritate the stomach lining and induce ulcer formation. Liver disease can interfere with the production of clotting factors, resulting in a coagulopathy that allows minor GI irritation to become a major bleed.
Toxins and certain medications are significant contributors to this symptom. Anticoagulant rodenticides (rat poison) prevent the body from recycling Vitamin K, which is necessary for producing clotting proteins. This leads to widespread, uncontrolled bleeding, often manifesting as hematemesis. Human non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen are highly toxic to cats and rapidly cause severe gastrointestinal ulceration and hemorrhage.
Immediate Steps and Veterinary Treatment
If you observe your cat vomiting blood, contact your veterinarian or an emergency animal hospital immediately. Do not attempt to treat the condition at home or offer food or water unless instructed by a veterinary professional. The digestive tract needs to rest, and administering anything orally could worsen the bleeding or complicate the diagnostic process.
Before leaving for the clinic, gather as much information as possible to relay to the veterinary team. This includes the frequency of the vomiting, the exact appearance of the blood (bright red, coffee grounds, or frothy), and any recent changes in diet, medication, or access to potential toxins. If possible, take a clear photograph of the vomit or collect a small sample in a clean container, as this visual evidence is invaluable for diagnosis.
Upon arrival, the veterinary team will stabilize your cat, which often involves administering intravenous (IV) fluids to combat dehydration and shock from blood loss. Diagnostic workup typically begins with blood tests, including a Complete Blood Count (CBC) to check for anemia and a chemistry panel to assess organ function, such as the liver and kidneys. A coagulation profile is often run to determine if a clotting disorder is the source of the hemorrhage.
Imaging studies, such as abdominal X-rays and ultrasound, are used to look for foreign objects, tumors, or structural abnormalities within the GI tract. The veterinarian may also recommend an endoscopy, where a flexible tube with a camera is passed down the esophagus to visually inspect the stomach and upper intestine. This procedure allows for direct visualization of ulcers or erosions. Endoscopy also enables the collection of tissue biopsies or the removal of certain foreign bodies, which helps determine the cause and guide the treatment plan.