A cat throwing up blood is a veterinary emergency. Whether it’s a small streak of red or a larger amount of dark, grainy material, blood in vomit signals bleeding somewhere in your cat’s digestive tract and requires immediate veterinary attention. A “wait and see” approach can have fatal consequences when the cause is something like a bleeding ulcer or a ruptured mass.
What Blood in Cat Vomit Looks Like
Blood in vomit doesn’t always look the way you’d expect. Fresh, bright red blood typically comes from the mouth, throat, esophagus, or stomach and suggests active bleeding. Darker blood that looks like coffee grounds has been partially digested by stomach acid, which points to bleeding that’s been happening for longer or originates deeper in the digestive tract. Sometimes the blood is just faint pink streaks mixed into otherwise normal-looking vomit.
It’s also worth noting that vomiting and coughing can look very similar in cats, and owners frequently confuse the two. Blood coughed up from the lungs is a completely different problem from blood vomited from the stomach. If your cat seemed to be retching with abdominal contractions, that’s vomiting. If the episode involved more of a hacking motion with an extended neck and no abdominal heaving, it may have been a cough. This distinction matters because it changes the diagnostic direction entirely.
Stomach and Intestinal Causes
The most straightforward explanation is direct damage to the lining of the stomach or upper intestine. Gastric ulcers are a well-documented cause in cats, and they develop for a wide range of reasons: stress, inflammatory bowel disease, chronic infections, or even certain parasites like roundworms. In a review of feline gastric ulcer cases published in the veterinary literature, fewer than a third of cats with confirmed ulcers actually showed visible blood in their vomit or stool, meaning ulcers can bleed without obvious signs for some time before things escalate.
Foreign objects are another common culprit. Cats swallow string, thread, rubber bands, small toy parts, and pieces of bone. A foreign body can physically scrape or puncture the stomach lining, causing bleeding. Linear foreign bodies (like string or ribbon) are especially dangerous because they can bunch up the intestines and cut through tissue. Hairballs, while usually harmless, can occasionally irritate the stomach lining enough to produce small amounts of blood.
Inflammatory bowel disease, a chronic condition where the immune system attacks the gut lining, can also lead to bleeding over time. And tumors in the stomach or intestines, including lymphoma and adenocarcinoma, damage tissue integrity and blood flow, sometimes causing ulceration that bleeds into the digestive tract. Mast cell tumors are the most frequently reported tumor type associated with stomach ulcers in cats.
Toxins and Medications
Poisoning is one of the more urgent possibilities. Anticoagulant rodenticides (rat and mouse poisons) work by preventing blood from clotting, and a cat that eats a poisoned rodent or the bait directly can develop uncontrolled internal bleeding. Signs can include blood in vomit, dark tarry stool, tiny red spots on the gums or skin, and general weakness. While rodenticide poisoning is relatively rare in cats compared to dogs, it’s life-threatening when it does occur.
Human medications are a surprisingly common cause. Pain relievers like ibuprofen and naproxen are extremely toxic to cats and can rapidly cause stomach ulcers and internal bleeding, even in small doses. Acetaminophen (Tylenol) is also dangerous and can damage red blood cells so severely that a cat’s gums turn brown. Prescription corticosteroids and veterinary pain medications can cause similar problems, particularly in overdose situations. Never give your cat any human medication unless specifically directed by a vet.
Household toxins matter too. Certain plants, including Dieffenbachia, have been linked to gastric damage in cats. Pesticides, both household and agricultural, account for a significant portion of feline poisoning cases.
Kidney and Liver Disease
Blood in vomit isn’t always caused by a problem in the stomach itself. Chronic kidney disease, one of the most common conditions in older cats, can trigger a chain reaction that leads to stomach bleeding. As the kidneys lose function, waste products build up in the blood. This causes a condition called uremia, which increases stomach acid production and inflames the stomach lining. The resulting gastritis can progress to ulceration and bleeding. Gastrointestinal signs like vomiting, loss of appetite, and nausea are often the most noticeable symptoms of uremia, and frequently the reason owners bring their cat to the vet in the first place.
Liver disease can also contribute. The liver produces clotting factors, so when it’s damaged, blood may not clot properly. Yellow-tinged gums are one visible sign of liver problems, caused by a buildup of bilirubin from damaged red blood cells or impaired liver function.
What to Do Right Now
Don’t wait to see if it happens again. Any amount of blood in your cat’s vomit warrants a same-day veterinary visit, and several situations call for an emergency trip:
- Pale or white gums: Press a finger briefly against your cat’s gum. Healthy gums are pink and the color returns within one to two seconds after you release pressure. White or very light pink gums suggest blood loss or shock.
- Weakness or lethargy: A cat that’s less responsive than normal, reluctant to move, or seems “out of it” may be losing blood internally.
- Repeated vomiting: Multiple episodes, especially if each contains blood, indicate ongoing bleeding.
- Refusal to eat or drink: Combined with bloody vomit, this suggests significant distress.
- Tiny red spots on the gums, eyes, or skin: These pinpoint dots (petechiae) or bruising signal a clotting disorder.
- Known toxin exposure: If your cat may have eaten rat poison, a human medication, or a toxic plant, don’t wait for symptoms to worsen.
Before you leave for the vet, note the color of the blood (bright red vs. dark/grainy), how much there was, and how many times your cat has vomited. If possible, take a photo of the vomit. Gather any information about potential toxin exposure: open medication bottles, chewed plants, or rodent bait stations your cat could have accessed. Do not try to induce vomiting or give any medication at home.
How the Vet Finds the Cause
Your vet will likely start with blood work to check organ function, red blood cell counts, and clotting ability. These results can quickly reveal kidney disease, liver problems, anemia from blood loss, or clotting disorders consistent with poisoning.
Abdominal X-rays can identify certain foreign objects, and they’re particularly useful for spotting the telltale bunching of intestinal loops caused by linear foreign bodies like string. When X-rays are inconclusive, ultrasound is the next step. It’s the most widely used tool for imaging the GI tract in cats and can help identify masses, foreign bodies, and areas of abnormal intestinal wall thickening.
However, ultrasound has limits. Inflammatory bowel disease and intestinal lymphoma can look very similar on imaging, so a definitive diagnosis often requires tissue samples, either through endoscopy (a camera passed into the stomach) or surgical biopsy.
Recovery and What to Expect
Recovery depends entirely on the underlying cause. A cat that swallowed a foreign object may need surgery but can recover fully within a couple of weeks. Rodenticide poisoning, when caught early, is treatable with vitamin K therapy over several weeks. Stomach ulcers caused by medication usually heal once the offending drug is stopped and acid-reducing treatment begins.
For chronic conditions like kidney disease or inflammatory bowel disease, management is ongoing. Your vet may recommend a prescription or bland diet, fed in smaller, more frequent meals throughout the day rather than one or two large ones. Treats and table scraps should be avoided during recovery, as they can worsen GI irritation. Keeping a food diary and weighing your cat regularly helps your vet track whether nutrition and weight are staying on course.
Conditions like intestinal lymphoma or advanced kidney disease carry a more guarded prognosis, but treatment can still improve quality of life and extend comfortable time. The single most important factor in outcomes across all these causes is how quickly treatment begins.