Dr. Utchen: My cat vomits several times a week, but seems okay otherwise. Is this just furballs?
It is not likely that this is just furballs. Although cats do get furballs, and will sometimes vomit as a result, most cats will not vomit several times a week from this. There are a number of problems that can cause frequent vomiting cats, and only a veterinarian can diagnose these problems. Usually this requires X-rays and blood tests, and sometimes ultrasound. Less commonly, more invasive diagnostics like endoscopy and intestinal biopsies are necessary.
One common problem causing cats to vomit frequently—without any apparent untoward effects otherwise—is Inflammatory Bowel Disease (or Inflammatory Bowel Syndrome), abbreviated IBD so this may be what your cat has.
This is an inflammatory condition of the wall of the small intestine of unknown cause. An oversimplified explanation that I use with my clients is: this is to the intestinal system what a rash of unknown cause is to the skin. If it's bad enough in a cat's intestines, it will cause frequent vomiting, or diarrhea, or both.
And while we don't know what causes this, there are several simple things to be done initially that may be a "quick-fix".
First, try canned food instead of dry food. Cats evolved eating a diet of small mammals, birds, and bugs. This is far more like the consistency of canned cat food than it is like dry cat food. In fact, it is surprising to me that most cats can enjoy dry food and NOT have digestive problems.
Second, try a hypoallergenic diet for your cat. Some cats with frequent vomiting problems have a food allergy, and the vomiting can completely resolve when fed a special food. Most veterinary offices carry special cat foods made of ingredients that won't cause food allergies in cats. Odd though it may seem, these diets are often made of ingredients like venison (deer meat), rabbit, or duck.
The best solution is to consult your veterinarian for X-rays, stool tests, and blood tests. There are many causes for frequent vomiting, including having swallowed foreign objects (my cat once swallowed 8 pennies—yes I did surgery to remove them and she lived a long life). These are not problems you should wait several weeks for while trying different cat foods.
However, if all the tests indicate that the problem is IBD, the treatment is to administer cortisone in one form or another. This can be given as an injection every few months or as a daily tablet. Usually this medication can be obtained in chewable form.
Some cats cannot tolerate the systemic effects of cortisone, in which case a medication called "Budesonide" can be given daily. This is a form of cortisone that only coats the lining of the digestive system, and does not get digested into the blood stream like the other forms of cortisone do. For the intestinal system, this is effectively like putting a cortisone cream on a skin rash, compared to taking cortisone pills or shots to control it.
Regardless of the cause for long-term vomiting, some cats will develop a vitamin B-12 deficiency as a result, which impairs the health of the intestinal lining. This in turn prevents the intestines from absorbing B-12 from the diet, with perpetuates the B-12 deficiency. Until a cat in this situation is given weekly injections of vitamin B-12, the health of their intestinal lining will not return to normal, even if the proper food has been fed and the underlying problem has been otherwise corrected.
Unfortunately, cats can get other internal organ problems that can manifest as frequent vomiting as well as the same kinds of intestinal cancer that people can. So if your cat is older, or in general ways is becoming debilitated (losing weight, becoming listless, losing his or her appetite), please consult with your veterinarian as soon as possible. Most things are treatable to different degrees, but as with other medical problems, an ounce of prevention is worth a pound of cure, and the sooner you solve the problem the better.