Chronic vomiting is defined as vomiting twice or more monthly. It is very common and frequently incorrectly attributed to eating too fast, nervous stomach, just hairballs or “just a puker.” Most commonly, it is due to small intestinal disease. Vomiting of whole dry food is not due to eating too fast. Cats typically just swallow without chewing 80% of dry food consumed. Eating grass doesn’t cause vomiting. They eat it because they like it.
Regarding hairballs, cats have an apparent lack of organized interdigestive motility. In dogs and people, organized contractions effectively eliminate non-digestible contents larger than 1 to 2 mm in diameter. Absence of organized contractions in cats can prevent passage of hair material through the pyloris (outflow opening from the stomach) and promote retention and ultimately, formation of a hairball. Chronic small intestinal disease causes reduced small intestinal motility which then causes frequent vomiting in short-haired cats. Originally domestic cats had short hair and so only in long-haired cats will the elimination of extra hair be too much for a healthy long-haired cat’s digestive system. Overgrooming can cause an excessive amount of hair in the digestive tract leading to hairball vomiting whether the cat is short-haired or long-haired. Overgrooming can be caused by feeling itchy, stress or locations of pain. The use of petroleum-based hairball prevention products is not recommended as it is not “due to a grease deficiency.” If vomiting hair balls is less than once every 2 weeks, then brushing, clipping the hair short in a long-haired cat and adding water to canned food can be tried. If vomiting more than every 2 weeks, then it is unlikely to be caused by hairballs and time to evaluate for underlying cause. Also, if vomiting food greater than 12 hours after eating, then it is likely due to chronic small intestinal disease which reduces small intestinal motility resulting in delayed stomach emptying. If vomiting is chronic and otherwise appetite is good and there has been no weight loss, then can do a 1 month dietary trial with a novel protein diet or hydrolyzed protein diet to check for dietary intolerance, but this is an uncommon cause for vomiting. In kittens a stool evaluation for parasites can be helpful and a trial of worming medication can be given as parasites are not always detected on fecal testing.
Evaluation for the cause of chronic vomiting follows a standard approach. First radiographs or x-rays are always indicated as the test is very sensitive and specific for detecting an obstruction. Abdominal ultrasound is a very useful complement to radiographs as structural changes can be detected including checking for thickening of the intestinal wall and possible enlargements of the mesenteric lymph node that receives lymphatic drainage from the small intestine. If the small intestinal wall is thickened then 96% chance this is either small intestinal inflammatory disease or lymphoma, a cancer. If the mesenteric lymph node is enlarged the ultrasound can be used to guide a needle into the lymph node and get an aspirate sample. This can be a very non-invasive approach to getting information to make treatment decisions.
Chronic vomiting is very common in cats, affecting 1 out of 5 cats over 10 years of age. It is not normal and 99% of time is due to a problem at the small intestine. Absolute diagnosis of a small intestinal problem necessitates biopsies at the correct location and the full thickness of the small intestinal wall. Generally, though an appropriate diagnosis to proceed with therapy can be obtained by abdominal ultrasound and an ultrasound-guided aspirate of the lymph node associated with the small intestine. With either inflammatory small intestinal disease or small cell lymphoma treatment is generally very effective and both are associated with a good prognosis.
