Brown liquid in cat vomiting can be a sign of serious illness. Vomiting itself is considered a nonspecific symptom. It may be related to a range of health problems. Some of these may include allergic reactions, internal resistance, pancreatitis, ren...
Brown liquid in cat vomiting can be a sign of serious illness. Vomiting itself is considered a nonspecific symptom. It may be related to a range of health problems. Some of these may include allergic reactions, internal resistance, pancreatitis, renal failure, parasitic infections, liver disease, inflammation, poisoning, or neurological diseases, but what exactly causes the cat to vomit brown fluid?
Causes of vomiting brown fluid in cats
1. Gastrointestinal bleeding: Brown vomit may indicate bleeding. If your cat vomits for a period of time, there may be inflammation in the mouth and/or esophagus and may seep blood. If your cat does not vomit for a long time, brown fluid vomit may indicate further internal bleeding in the gastrointestinal tract. This may be caused by intestinal obstruction and inflammation and trauma due to foreign body intake or large hairball impact.

2. Brown bile: Sometimes brown liquid vomit may be bile in cat's liver. However, the bile that is vomited is usually yellow, so if you are sure that the brown liquid that the cat vomits is bile, it may be a sign of problems with the cat's internal organs.
3. Food: Of course, most cat food, whether it is dry or canned, are brown. If your cat is a habitual "scarf and vomit" cat, or they have gut sensitivity, it may cause them to vomit partially digested or undigested foods. If a veterinarian ruled out other medical issues and thought the cat was vomiting was actually food, then they might want your cat to take a strict hydrolyzed protein diet.
When it comes to food allergies, most cats are actually allergic to protein, not any other source of nutrition. A hydrolysis diet is a food that passes through the process of breaking down proteins into their individual amino acid components. This prevents your cat's immune system from identifying food as containing allergens and prevents your cat from having allergic symptoms.
What should I do if my cat vomits brown liquid?

Cats vomiting
Some cat owners may describe their cats as "vomiting", but it should be noted that frequent vomiting is by no means normal for cats. Chronic vomiting or vomiting that has been happening for more than two or three weeks is definitely a sign of the problem. If your cat vomits brown fluids multiple times and/or has other symptoms such as loss of appetite, weight loss, lethargy or diarrhea, you should make an appointment with your veterinarian immediately. Veterinarians will want to check the cat's vital signs from a physical examination, including body temperature, and palpate the cat's abdomen.
After a thorough examination, your veterinarian may also want to do some tests, including blood tests and x-rays. A blood test will check your cat's organ function to ensure there are no signs of liver or kidney disease, as well as your cat's red blood cells and platelet levels. The X-ray study will check for any fluid in the abdomen that may be blood, and it may also show intestinal gas patterns, which may indicate blockage.
Depending on your doctor's findings, your cat may need to be hospitalized for fluid therapy and supportive care, or they may only require outpatient treatment and oral medications to go home. If your veterinarian suspects that your cat has an intestinal obstruction, your cat may need surgery to remove any blockages.
Even if it is a benign thing like eating breakfast too quickly, routine vomiting in cats is by no means a normal activity. If you are struggling with a vomiting cat, call your veterinarian to see if they can help you determine that your cat is sick.