Cats throw up brown liquid for many reasons, and it can be associated with several health concerns. Brown-colored vomit often consists of bile or partially digested food and may be caused by minor issues like hairballs, or more serious concerns such as intestinal obstructions or pancreatitis. Read on to learn what may be causing your cat to throw up brown liquid, how you can help your cat at home, and when to call a veterinarian.

Why Do Cats Throw Up Brown Liquid?

When cats throw up brown liquid, it may contain food, bile, stomach acids, or even blood. The color and consistency of the vomit can help point to a cause, so it may be helpful to take a photo for your veterinarian. Vomiting brown liquid could be related to many health concerns. Some of the more common of these may include:

Hairballs

Many cats throw up hairballs from time to time, and sometimes they'll vomit brown liquid around the same time. This liquid may contain a combination of food particles and stomach acids, which often have a brownish tinge. Occasional hairballs are normal for most cats and can be managed with diet changes, supplements, and regular hair brushing. Contact your veterinarian if the hairballs occur frequently or if your cat shows other signs of illness.

Food-Related Issues

Most cat food, whether dry kibble or canned, is some shade of brown. If your cat eats too quickly or has a sensitive stomach, they may throw up partially digested or undigested food due to indigestion. Some food allergies can also cause indigestion. Or, your cat may be vomiting food due to a recent diet change. If the transition was made too quickly, your cat's digestive system may not have had enough time to adjust to the new food. In addition, some human foods are not healthy for cats and can lead to vomiting.

Gastrointestinal Obstruction

If a cat has eaten something indigestible, such as a string or toy, the object may become lodged in the GI tract. This blockage prevents normal digestion and may cause your cat to vomit, which may be any color or consistency depending on the stomach contents.

Organ Disease

Sometimes brown liquid vomit can be bile, which comes from your cat's liver. Vomited bile is usually yellow in color, but it can appear brown when mixed with food or stomach acids. Vomiting of any kind, including brown liquid, could mean there's a problem with your cat's internal organs, such as liver or kidney disease.

Bleeding in the Gastrointestinal Tract

Reddish-brown vomit may contain blood mixed with digestive juices or food. This often means the cat is bleeding somewhere in the gastrointestinal tract. GI bleeding is often caused by inflammation or an injury to the GI tract due to issues such as inflammatory bowel disease, poisoning, medication side effects, or tumors. These cats may also have blood in the stool.

If you are unsure whether the vomit has a red tinge, use a white paper towel to clean it up. You should be able to see the color better this way, especially if you add a little water to it. Contact your veterinarian immediately if you think your cat is vomiting blood.

What To Do if Your Cat is Vomiting Brown Liquid

If your cat has vomited once and is otherwise acting normal, then withhold food until the next mealtime (no more than 12 hours) and observe your cat. Contact your veterinarian if the vomiting continues or your cat shows other signs of illness, such as poor appetite, weight loss, lethargy, or diarrhea. Regular or frequent vomiting is never normal for a cat and always requires veterinary intervention.

Treatment for Vomiting in Cats

Your veterinarian will discuss your cat's history and perform a physical exam, which includes palpating your cat's abdomen. After a thorough examination, your vet may also want to run some tests, including blood work and X-rays. Blood work will check your cat's organ function, making sure that there are no signs of liver disease or kidney disease, as well as your cat's red blood cell and platelet levels. An X-ray study will check for any fluid in the abdomen that could potentially be blood and it may also show intestinal gas patterns that could be indicative of a blockage. In some cases, abdominal ultrasound may be recommended for further imaging.

Depending on what your doctor finds, your cat may require hospitalization for fluid therapy and supportive care. Some cats are able to go home with medications after receiving outpatient treatments. If your vet suspects your cat has an intestinal blockage your cat may require surgery to remove whatever the blockage is. 

Eating Too Quickly

If your cat is eating too quickly, food puzzles or slow feeders can help. Food puzzles are a great source of both play and enrichment for your cat because they stimulate both your cat's predatory and foraging instincts. If your cat routinely eats out of food puzzles or slow feeders and is still vomiting food, talk to your vet about the next steps.

Food Allergies and Sensitivities

If your vet has ruled out other medical issues and thinks your cat has a sensitive stomach or food allergy, they may recommend a special diet for your cat. Be sure to feed the diet exactly as instructed. Offer no other food or treats unless your vet has recommended it.

How to Prevent Vomiting in Cats

You can't always prevent illnesses that cause vomiting in cats, but there are steps you can take to reduce the chances of vomiting.

• Bring your cat to the veterinarian for routine wellness exams (once or twice per year)
• Contact your vet at the first sign of illness
• If your cat scarfs down food, try a slow feeder or food puzzle
• Keep toxic items out of your cat's reach (this includes some foods, medicines, plants, and chemicals)
• When changing food, be sure to transition slowly so your cat's digestive system can adjust.

If you're struggling with a vomiting cat, call your veterinarian to see if they can help you determine what is ailing your cat can how you can help them feel better.