Why is my cat vomiting red liquid?

Red vomit may first be from red foods like dyed kibble, canned meat, or carrots, which resolves after digestion and defecation. Second, it may be a stomach ulcer or mouth injury. If you confirm blood in the vomit, take the cat to the vet for targeted treatment. Also, viral diseases like feline panleukopenia can cause red vomit; this is an emergency, so do not observe at home but take the cat to the vet promptly.