Vomiting and Diarrhea in Dogs and Cats: What Every Pet Owner Should Know

Most pets experience an upset stomach at some point. Sometimes it’s something minor, like eating too quickly or coughing up a hairball. Other times, vomiting or diarrhea is a sign of something much more serious. These symptoms can escalate quickly, leading to dehydration, pain, or even life-threatening emergencies.

At Advanced Veterinary Medical Center, our team evaluates vomiting and diarrhea cases every day. With same-day appointments and full urgent care services, we can quickly determine whether your pet’s symptoms are minor or if they need immediate, advanced treatment.

Why Do Pets Vomit or Have Diarrhea?

Pets may vomit or have diarrhea when the stomach or intestines become irritated or inflamed. This can result from something as simple as eating too fast, or from complex diseases that require medical management.

Common triggers include:

  • Eating too quickly or scavenging food
  • Sudden diet changes or food intolerances
  • Stress, anxiety, or motion sickness
  • Hairballs in cats
  • Parasites or bacterial infections
  • Exposure to toxic plants, human medications, or chemicals
  • Underlying diseases affecting the kidneys, liver, pancreas, or thyroid

Because pets naturally hide illness, it’s easy to underestimate how serious GI signs may be. A single episode may resolve, but repeated vomiting or watery diarrhea, especially if accompanied by lethargy or blood, should always be taken seriously.

Underlying Health Problems Linked to GI Upset

Persistent vomiting and diarrhea often point to a deeper health issue. Some of the most common include:

  • Pancreatitis – Pancreatitis in pets is a painful condition that causes vomiting, diarrhea, lethargy, and appetite loss. It can be triggered by high-fat foods, certain medications, or underlying disease.
  • Kidney disease – Cats are especially prone to chronic kidney disease, which often causes gradual vomiting, weight loss, and reduced appetite. Early blood work and urinalysis are essential to catch this condition before it progresses.
  • Hyperthyroidism – In older cats, hyperthyroidism increases metabolism, leading to hunger, weight loss, restlessness, and frequent vomiting or diarrhea.
  • Liver disease – Liver disease in dogs and liver and gallbladder disease in cats may begin silently but cause vomiting, jaundice, and appetite loss as they progress. Left untreated, organ damage can be permanent.
  • Lymphoma – Lymphoma, one of the most common cancers in cats, often targets the GI tract. Both cats and dogs may develop weight loss, decreased appetite, vomiting, and diarrhea.
  • Inflammatory Bowel Disease (IBD) – IBD in cats and dogs causes chronic vomiting, diarrhea, and weight loss. It may be linked to immune responses, dietary sensitivities, or underlying inflammation.
  • Parasitic infections – Diarrhea in dogs and cats is often linked to parasites like giardia, hookworms, and roundworms. These spread through contaminated soil or water. Year-round parasite prevention is one of the best defenses.
  • Food intolerance or indiscretion – Eating garbage, table scraps, or sudden diet changes commonly causes vomiting and diarrhea. Food allergies can also cause chronic GI upset.
  • Infections – Bacterial and viral infections range from mild to life-threatening. Parvovirus in dogs is a severe cause of bloody diarrhea and requires urgent hospitalization.
  • Toxin ingestion – Exposure to toxic plants, medications, or chemicals can cause sudden GI upset.
  • Foreign body ingestion – Toys, bones, socks, and string can lodge in the stomach or intestines, leading to repeated vomiting, diarrhea, abdominal pain, and lethargy. These cases often require advanced surgery.

When GI Symptoms Mean It’s Time for the Vet

See a veterinarian right away if your pet’s vomiting or diarrhea is:

  • Bloody, black, or tarry
  • Accompanied by lethargy, fever, or abdominal pain
  • Persistent for more than 24–48 hours
  • Severe enough to cause dehydration or weight loss
  • Repeated retching without producing anything (a warning sign for bloat)

Explosive or large-volume diarrhea can cause dangerous electrolyte loss, particularly in puppies, kittens, and senior pets. Chronic vomiting or diarrhea, even when mild, should not be ignored, as it may point to kidney disease, IBD, or cancer that requires medical management.

Emergency Conditions That Can’t Wait

Some GI problems can’t wait. Immediate care is needed for:

  • Foreign Body Obstruction – Ingested objects can block digestion, requiring imaging and often surgical removal.
  • Bloat (GDV) – A rapidly fatal emergency in deep-chested dogs. GDV requires immediate surgery. Signs include retching, abdominal swelling, and collapse.
  • Parvovirus and Severe Infections – Unvaccinated dogs risk parvo, which causes bloody diarrhea, vomiting, and collapse. Puppies are especially vulnerable and need aggressive hospitalization.

At-Home Care for Mild Digestive Upset

If your pet is otherwise bright and alert, you can sometimes manage mild GI upset at home:

  • Withhold food for 12–24 hours, then reintroduce bland meals.
  • Offer small, frequent sips of water or pet-safe electrolytes.
  • Track symptoms to share with your vet.
  • Use a DIY dog checkup to monitor hydration and gum color.

If symptoms return or worsen, or new ones appear, call for urgent care immediately.

Risks of Ignoring Vomiting and Diarrhea

Without treatment, repeated vomiting and diarrhea can lead to:

  • Severe dehydration and electrolyte imbalance
  • Malnutrition and weight loss
  • Secondary infections
  • Organ strain from chronic disease (kidney, liver, pancreas, thyroid)
  • Progression of hidden cancers or infections

In cats, frequent vomiting is often dismissed as “normal.” In reality, it’s a red flag that may signal kidney disease, IBD, or hyperthyroidism. Early intervention makes a huge difference in outcome.

How Your Vet Helps Manage Digestive Illness

At Advanced Veterinary Medical Center, our goal is to provide not just treatment but long-term support.

Diagnostics and Routine Health Checks

Our diagnostic services include digital X-rays, ultrasound, and in-house lab testing, allowing us to quickly identify the cause of GI distress. Routine bloodwork helps detect organ problems before they escalate.

Urgent and Surgical Care

Our urgent care services ensure your pet can be seen the same day for vomiting, diarrhea, or other sudden illnesses. If surgery is required, our surgical team is equipped to handle foreign bodies and other emergencies.

A fluffy orange cat sits on an exam table at a veterinary clinic, being gently held by a vet in scrubs and gloves, while a child and an adult stand nearby, watching with concern.

Preventive Care to Reduce GI Problems

Prevention is just as important as treatment. Our wellness packages, kitten packages, and puppy packages include parasite prevention, vaccinations, and nutritional guidance to reduce future GI problems.

A Veterinary Team Focused on Comfort and Support

Our experienced team is committed to giving families clear answers and peace of mind. We believe in real medicine, real access, and real partnership, so you’ll never feel alone in making decisions for your pet.

Fast Action Protects Your Pet’s Health

Vomiting and diarrhea may start as minor problems, but they can escalate quickly. Trust your instincts—if your pet seems weak, lethargic, or unable to keep food or water down, do not wait.

Contact Advanced Veterinary Medical Center or schedule an appointment. With urgent care, advanced diagnostics, and experienced surgical support, we are here to restore your pet’s health and peace of mind.

Phone: 408-668-1465
Address: 800 E. Capitol Avenue, Milpitas, CA 95035
Hours: Mon–Fri 7:30 am–7:00 pm | Sat–Sun 7:30 am–6:00 pm