Management of Vomiting in Cats

Differential Diagnosis

Vomiting is the forceful ejection of stomach and proximal duodenal contents through the mouth. Vomiting can be induced by vestibular, vagal, chemoreceptor trigger zone, or direct input to the emetic center. Gastrointestinal (GI) signs can be the result of primary diseases of the GI system or secondary GI diseases. The secondary GI diseases associated with vomiting are generally those of the kidneys, liver, pancreas (pancreatitis), endocrine system (hyoadrenocorticism; diabetic ketoacidosis; hyperthyroidism), or central nervous system. Differential diagnoses for primary GI diseases are often grouped into obstruction (masses, foreign body, and intussusception), dietary intolerance, drugs/toxins (garbage gut), inflammatory gastric and bowel diseases, neoplasia, infectious diseases, and parasites. The primary bacteria associated with gastrointestinal tract disease in cats include Salmonella spp., Campylobacter jejuni, Clostridium perfringens, Helicobacter spp., bacterial overgrowth syndrome, bacterial peritonitis, and bacterial cholangiohepatitis. The primary viral agents include feline coronaviruses, feline leukemia virus, feline immunodeficiency virus, and feline panleukopenia virus. The primary nematodes are Ancylostoma/Uncinaria, Strongyloides cati, Dirofilaria immitis (vomiting), Toxocara cati, Toxascaris leonina, Ollulanus tricuspis, and Physaloptera spp. (Table 1). Enteric protozoans include Giardia spp., Cystoisospora spp., Cryptosporidium spp., Entamoeba histolytica, and Tritrichomonas foetus. The cestodes Taenia, Dipylidium, and Echinococcus generally cause subclinical infection. 

Occasionally, otherwise healthy cats with acute vomiting and normal physical examination findings can be handled conservatively by withholding food for 24 hours followed by introduction of a bland food for several days. For all cats with vomiting, I will perform a fecal flotation and complete blood cell count (CBC). While the CBC generally does not lead to a specific diagnosis, the presence of eosinophilia makes inflammatory bowel diseases and parasitism more likely.

Diagnosis

A biochemical profile, urinalysis, FeLV antigen assay, and FIV antibody assay are indicated if secondary GI diseases are on the differential list or if dehydration is present. I generally perform a total T4 on all cats with vomiting that are greater than 5 years of age. While amylase and lipase are poor predictors of pancreatitis in cats, a pancreatic lipase immunoreactivity assay has now been validated. It can be used to diagnose pancreatitis (increased) in cats. The positive predictive value is better for acute pancreatitis than chronic pancreatitis. If a cat with suspected pancreatitis has abdominal effusion, assay lipase concentrations in the serum and effusion; if pancreatitis is occurring the effusion lipase is usually greater than serum. While rare in cats, an ACTH stimulation test can be used to exclude hypoadrenocorticism from the differential list. [...]