[From Tufts February 2010 Issue]
Do you know why my overweight cat vomits? She is elderly, but I don’t know her exact age. I feed her half of a 3-ounce can of Fancy Feast at night and three-quarters of a cup of a dental-diet dry food during the day. The vomit looks like it has been digested (like small chewed pieces of dry food in very yellow fluid). Fortunately, she can sometimes go 10 days without an episode. I appreciate any advice you can offer.
Name withheld upon request
Dear Reader: When a cat vomits, you can break the cause into two main categories: It is either a gastrointestinal problem, or it’s not a gastrointestinal problem. Your cat is elderly, and there are many common metabolic causes of vomiting, such as chronic renal failure or hyperthyroidism. These disorders can usually be diagnosed through simple blood and urine tests.
If your cat does not have a metabolic cause for the vomiting, then a gastrointestinal cause should be pursued. The first thing you should consider is a bland, non-irritating, easily digestible diet. There are several commercially available therapeutic diets, such as Hill’s Prescription Diet i/d, Iams Low Residue formula, or Purina Gastrointestinal EN. If this doesn’t curb the vomiting, a hypoallergenic diet can be tried. This diet contains a protein and carbohydrate source that the cat has never been exposed to, such as rabbit and green pea, duck and green pea or venison and green pea.
If this doesn’t control the vomiting, advanced diagnostics such as abdominal ultrasound or gastrointestinal endoscopy, may be necessary. The fact that your cat is not losing weight and that the vomiting is fairly infrequent suggests that her problem is not a serious one. She may respond to altering her diet, plus receiving an anti-vomiting drug such as Cerenia. If other signs were to develop, like weight loss, poor appetite or diarrhea, or if the vomiting becomes more frequent and severe, consult your veterinarian about pursuing the advanced diagnostics discussed above.
Arnold Plotnick, DVM
Catnip Medical Editor