Cat vomiting and diarrhea are common, but common doesn’t always mean harmless. A single episode after eating too fast is very different from repeated vomiting paired with bloody diarrhea and a cat who won’t get off the couch, and knowing how to tell those situations apart could genuinely save your cat’s life. Before you decide whether to monitor things at home or head straight to the vet, there’s some important information every cat owner should have. Our team at Comal Pet Hospital & Resort in New Braunfels, TX breaks down the causes, the warning signs, and exactly when cat vomiting and diarrhea cross the line from “wait and see” into emergency territory, so keep reading.
Why Do Cats Vomit and Have Diarrhea?
Cats are unfortunately prone to gastrointestinal upset, and cat vomiting and diarrhea are among the most common reasons pet owners seek veterinary care. The causes range widely in severity and can involve the digestive tract, other organ systems, or even environmental factors.
Understanding what’s normal for your individual cat is important baseline knowledge. A cat who occasionally vomits a hairball is very different from a cat who vomits multiple times a day with concurrent diarrhea. Context, including frequency, the appearance of the vomit or stool, and your cat’s overall behavior, helps paint a much clearer picture.
Common Causes of Cat Vomiting and Diarrhea
Cat vomiting and diarrhea can stem from many different causes. Below are the most frequently seen in a veterinary setting:
Dietary Indiscretion or Food Change
Cats have sensitive digestive systems, and abrupt food changes are a leading cause of cat vomiting and diarrhea. If you recently switched your cat’s food, even to a higher-quality brand, doing so too quickly can cause significant GI upset. Always transition your cat to new food gradually over 7 to 10 days. Eating too fast, overeating, or getting into something they shouldn’t have can also trigger a short-lived episode.
Hairballs
Hairballs are the classic culprit behind cat vomiting in long-haired breeds, but they affect short-haired cats too. When a cat grooms excessively or sheds heavily, swallowed hair accumulates in the stomach. Occasional hairball vomiting is normal, but frequent hairball episodes, meaning more than once a week, may indicate an underlying skin or GI issue worth discussing with your veterinarian.
Intestinal Parasites
Roundworms, hookworms, giardia, and other parasites are common causes of cat diarrhea, particularly in kittens and outdoor cats. A fecal examination at Comal Pet Hospital & Resort can identify parasites quickly, and treatment is generally straightforward once the parasite is identified.
Viral and Bacterial Infections
Feline panleukopenia, salmonella, and other infectious agents can cause acute, severe cat vomiting and diarrhea. These infections are particularly dangerous in kittens and unvaccinated cats. Panleukopenia (feline distemper) is a medical emergency that requires immediate veterinary attention.
Inflammatory Bowel Disease (IBD)
Chronic cat vomiting and diarrhea that recurs over weeks or months may indicate inflammatory bowel disease. IBD in cats involves ongoing inflammation of the GI tract and typically requires diagnostic testing such as bloodwork, ultrasound, and sometimes intestinal biopsy to diagnose and manage properly.
Kidney Disease, Liver Disease, and Hyperthyroidism
Vomiting and diarrhea in cats aren’t always caused by GI problems. Kidney disease, liver disease, hyperthyroidism, and diabetes can all produce GI symptoms. This is especially important to consider in middle-aged to senior cats who develop sudden or worsening vomiting and diarrhea. Early bloodwork can catch many of these conditions before they become advanced.
Toxin Ingestion
Cats are curious, and ingestion of toxic plants, household chemicals, medications, or other hazardous substances can cause sudden, severe vomiting and diarrhea. If you suspect your cat has eaten something toxic, contact Comal Pet Hospital & Resort or the ASPCA Animal Poison Control Center immediately. Do not wait to see if symptoms resolve on their own.
What Does Normal vs. Concerning Cat Vomiting Look Like?
Not all vomiting is the same, and what comes up can provide important clues to your veterinarian about what’s going on.
Types of Cat Vomit and What They May Indicate
- Undigested or partially digested food: Often related to eating too fast or a food sensitivity
- Yellow or green bile: May indicate an empty stomach or liver/gallbladder involvement
- Clear or foamy liquid: Can be related to acid reflux, hairballs, or an empty stomach
- Blood or material resembling coffee grounds: A serious sign requiring immediate veterinary attention
- Worm-like contents: May indicate intestinal parasites
What Does Concerning Cat Diarrhea Look Like?
Just as with vomiting, diarrhea in cats varies in presentation. Small intestinal diarrhea tends to produce large volumes of loose stool, while large intestinal diarrhea typically involves smaller, more frequent stools that may contain mucus or blood. Bloody diarrhea, whether bright red or dark and tarry, always warrants urgent veterinary evaluation. Cat diarrhea that persists for more than 24 to 48 hours should be evaluated by a veterinarian, especially if accompanied by vomiting.
When Is Cat Vomiting and Diarrhea an Emergency?
Some situations require an urgent or emergency vet visit rather than a wait-and-see approach. Take your cat to Comal Pet Hospital & Resort right away if they are experiencing:
- Vomiting or diarrhea that is frequent, severe, or has lasted more than 24–48 hours
- Blood in the vomit or stool, including dark, tarry stools
- Lethargy, weakness, or collapse
- Signs of dehydration: sunken eyes, dry gums, skin that doesn’t spring back when gently pinched
- Abdominal pain, bloating, or a distended belly
- Suspected ingestion of a toxic substance, medication, or foreign object
- Loss of appetite lasting more than 24 hours in an adult cat, or any duration in a kitten
Cats can deteriorate quickly when vomiting and diarrhea lead to dehydration, especially kittens and senior cats. If you are ever in doubt about whether your cat’s symptoms are serious, call us. It is always better to have a veterinarian weigh in than to wait too long.
How Will a Vet Diagnose the Cause of My Cat’s Vomiting and Diarrhea?
At Comal Pet Hospital & Resort, diagnosing cat vomiting and diarrhea starts with a thorough physical exam and a detailed conversation about your cat’s history, diet, indoor/outdoor access, and the specifics of their symptoms. From there, your veterinarian may recommend:
- Fecal examination to check for intestinal parasites
- Bloodwork to evaluate organ function, blood cell counts, and systemic health
- Abdominal X-rays or ultrasound to look for obstructions, masses, or organ abnormalities
- Additional specialized testing if IBD, pancreatitis, or infectious disease is suspected
Helping Your Cat Feel Better Starts Here
Cat vomiting and diarrhea are symptoms, not diagnoses, and the right treatment depends entirely on what’s causing them. From a simple dietary adjustment to managing a chronic disease, the veterinary team at Comal Pet Hospital & Resort in New Braunfels, TX will work with you every step of the way. If your cat has been sick and you’re not sure what to do next, call us at (830) 625-8074 or book an appointment online. We’re here to help you get answers, get your cat feeling better, and give you the peace of mind that comes from knowing your cat is in good hands.
About Us
Medicine isn’t the only thing that contributes to a happy, healthy pet. At Comal Pet Hospital & Resort, we provide a complete inventory of essential preventive and medical services for dogs and cats, with all-inclusive boarding, dog daycare, and grooming situated right next door.