Why is my cat vomiting?

Acute vs chronic vomiting: different workup

Acute vomiting (sudden onset, less than 3-5 days) is often self-limiting dietary indiscretion, but can indicate foreign body, toxin ingestion, or pancreatitis. Any cat vomiting more than 2-3 times in 24 hours, or vomiting with lethargy, blood, or abdominal pain, needs same-day evaluation.

Chronic vomiting (weeks to months of intermittent episodes) is the presentation that used to be normalized as 'my cat has a sensitive stomach'. Modern feline medicine treats weekly-or-more vomiting as a diagnostic problem, most cases have an identifiable and treatable cause on workup (chronic enteropathy, hyperthyroidism, CKD, food-responsive enteropathy, small-cell lymphoma).

Red flags that mean go to the vet today

• Vomiting with lethargy, weakness, or refusal to eat, especially in obese cats (hepatic lipidosis risk).
• Blood in vomit, or vomit that looks like coffee grounds.
• Vomiting a specific food repeatedly with no change (foreign body suspicion, especially strings or thread).
• Straining, retching, or gagging with nothing coming up (obstruction or bloat).
• Weight loss alongside chronic vomiting.
• Diabetic cat vomiting (DKA risk).

What a workup includes

Baseline workup is a CBC, chemistry, T4, urinalysis, and fecal exam, typically with abdominal ultrasound if chronic. Endoscopic or surgical biopsy is often needed to distinguish IBD from small-cell lymphoma; the two look identical on ultrasound. A hydrolyzed or novel-protein food trial for 6-8 weeks is often used early as both diagnostic and therapeutic step. Antiemetic class medication (maropitant) is safe and effective for symptomatic relief while the workup proceeds.