Sometimes people get frustrated with us as vets because they’d like a simple answer to this question, and unfortunately, there’s not. Vomiting is a symptom of many, many diseases. Cats also vomit to bring up hairballs, which collect in their stomachs as a by-product of the grooming that they do.
When we’re trying to figure out what’s making a cat vomit, we separate the list of considerations into two main categories: causes of acute vomiting, and causes of chronic vomiting. By rough definition, acute vomiting has been going on for less than 7 days. Typically an acutely vomiting cat is also ill. Causes of acute vomiting include ingestion of an irritating substance, such as plant material, gastrointestinal foreign body, ingestion of a toxin or poison, infection due to bacteria, virus, or parasites, kidney or liver failure, and pancreatitis.
All of those things can also cause chronic vomiting. In this case, the cat may feel well between bouts of vomiting, but there’s typically an underlying cause. Add food allergies, inflammatory bowel disease, hyperthyroidism, and cancer to the above list when considering the causes of chronic vomiting.SOURCE: https://www.petcoach.co/