It’s early in the morning, and you’ve stepped in it again: a little patch of clear or yellow-tinged foam, left by your cat. Vomiting bile, the foamy-stuff that your cat leaves behind after a retch-session, is very common and contrary to popular belief, is NOT normal, even if it is only infrequent. Why do cats throw up foam? There are many answers, all of which require the sleuthing skills of your local veterinarian. Before your appointment, however, there are questions you can ask yourself to try and figure out the trigger. How long has my cat been throwing up? Has your cat been throwing up foam for months, years, or is this a new occurrence? How often does your cat throw up? Is there every any hair or food in the vomitus? What time of day does your cat puke? These are all questiosn that your veterinarian will ask, so be thinking about them befor eyour veterinary visit. One side note: a cat that hasn’t been vomiting that suddenly starts vomiting over and over or can’t keep anything down is a veterinary emergency. Get your cat to the doctor immediately! What does your cat eat? Did you cat start vomiting foam after a diet change? Some cats have sensitive stomachs or adverse reactions to certain ingredients, such as chicken, beef, or soy. If you cat started vomiting after you changed the cat food, then the new diet might be the culprit. Has your cat lost any weight? How is your cat’s appetite? Weight loss accompanying vomiting is cause for concern. Everything from hyperthyroidism, to kidney failure, to infections, to intestinal parasites, to cancer, to inflammatory bowel disease can cause vomiting, and your likeihood of a secondary serious problem is more likely if you cat is vomiting AND losing weight. What to Expect at the Veterinarian If your cat is throwing up foam, schedule a veterinary visit. At your visit, expect the staff to weigh your cat, take a thorough history and perform a physical exam. Your doctor may recommenda additional tests, including lab work and imaging studies such as x-rays. It is helpful if you bring in a fecal and urine sample: it will save the staff from having to collect those from your cat. Most of the time throwing up foam is not a big cause for concern, but always make sure to see your veterinarian if your cat has that problem.