Dr. Utchen, my cat keeps throwing up almost immediately after eating -- she seems to be happy and healthy otherwise. What could be causing this -- should I be concerned?
Your cat's situation does not sound like an emergency (although your carpet might think otherwise!). However, it would be a good idea to have your veterinarian take a look to be sure there isn't something wrong that can be corrected.
Cats can act well but still vomit frequently for a variety of reasons. For example, some cats develop sensitivities to particular foods that are no longer a good "fit" for that cat. Special easily digestible cat foods and hypoallergenic cat foods are available from most veterinarians. A simple trial of one of these foods for a week or two may solve the problem.
Other cats can have inflammatory problems of the intestines for which no clear cause can be found. It often requires X-rays and other tests to determine this, but in most cases there is medication to reduce the severity of the intestinal inflammation and stop the vomiting.
Occasionally I see a cat who can no longer tolerate dry cat food, but for whom a steady diet of canned food is completely curative for their vomiting problem.
Rarely, we see cats that develop stomach ulcers. Sometimes these are caused by the presence of certain specific bacteria in the stomach, and sometimes these are caused by a foreign object that a cat has swallowed.
All of these conditions can cause a cat to vomit right after eating, and all can be managed effectively.
One commonly held belief among cat owners and veterinarians that is coming under closer scrutiny is that hairballs are a frequent cause of vomiting in cats. Cats are habitual groomers (by one estimate, they spend 1/3 of their waking hours grooming themselves!), and all cats ingest significant amounts of fur daily. Why some of them vomit hairballs and others don't has never been clear. It may be that most cats have hairballs in their stomachs at any given time. Those that vomit hairballs may, in fact, be vomiting for some other reason, and the cause for the vomiting is being misattributed to the presence of the hairball.
Of course, there are numerous other problems that cats can have that cause vomiting, that may or may not occur immediately after eating as with your cat, and that often reduce a cat's appetite or otherwise adversely affect their attitude and energy level.
Presuming your cat is truly acting well and eating normally, you probably do not need to rush to the veterinarian. However, if you have a cat that vomits frequently, whether or not it occurs immediately after eating, and even if they otherwise act completely fine, you may not realize that this is not normal. The fact is that most cats do not vomit often—if at all, so it is no more normal for a cat to vomit daily than it would be for you to do so 365 times a year! So do your cat and your carpet a favor, and have your kitty checked. The solution could be as simple as a change of food or a simple medication.