Stomach flu is a form of gastroenteritis that occurs when your dog contracts a virus. This is usually characterized by vomiting and diarrhea. Because the symptoms are not specific to gastroenteritis, you should bring your dog to the veterinarian to rule out other, more serious conditions. Although symptomatic treatment for the stomach flu can be provided at home, it's best to leave it to a professional.

The two most common signs of gastroenteritis are vomiting and diarrhea. Additional signs to watch for include:

The term “stomach flu” typically refers to viral gastroenteritis, which is caused by infectious agents such as noroviruses, sapoviruses, and parvoviruses. Gastroenteritis itself, however, can occur for a variety of reasons, including:

Though viruses are not thought to be a common cause for gastroenteritis in dogs, a large number of them may affect the gastrointestinal tract.

Gastroenteritis is diagnosed by the sudden onset of vomiting or diarrhea. Since the symptoms of viral gastroenteritis are mirrored in a number of other conditions, you will need to provide your veterinarian with information to help narrow the possibilities down. Come prepared with as much information as possible to help the veterinarian diagnose. It all comes down to preparation, the better prepared you are, the more likely a swift and accurate diagnosis will be delivered. This information may include:

The veterinarian will establish a history and a medical profile for your dog, both of which can assist in diagnosing stomach flu.

Fecal testing can reveal the presence of viruses in your dog’s gastrointestinal tract, though this method is not always reliable and cannot detect all types of viral agents. The veterinarian will most likely perform blood work and a urinalysis during the initial examination to rule out other, more serious conditions. The urinalysis will be helpful for detecting urinary tract infections, kidney disease, or general dehydration. Through the process of elimination, the veterinarian may attempt either abdominal radiographs, or abdominal ultrasounds. These tests will help the veterinarian search for any stomach or intestinal obstructions or other abnormalities. After this testing, the veterinarian may work towards a diagnosis of gastroenteritis, if not of stomach flu specifically. Laboratory testing and imaging are not necessary for a diagnosis of gastroenteritis but do eliminate other causes for exhibited symptoms.

Treatment for viral gastroenteritis is primarily supportive and focuses on the symptoms rather than the condition itself. Since your dog loses fluids through vomiting and diarrhea, rehydration is vital, as is proper maintenance of blood electrolyte balance. Fluids may be replenished orally or intravenously depending on the degree of dehydration.

The veterinarian may recommend that you withhold food for a day to allow your dog’s gastrointestinal tract to rest and recover. After this time, you can introduce soft, bland foods and gradually work back up to your dog’s normal diet. Medications are prescribed in severe cases to decrease your dog’s nausea and urge to vomit. Most cases of viral gastroenteritis can be resolved at home without the intervention of medication, provided your dog remains sufficiently hydrated.

Overcoming dehydration is important, be sure to provide your dog with plenty of fresh water, and limit or withhold food for several hours. The vomiting and diarrhea should improve within a day or two of treatment, at which time you can feed your dog small amounts of bland food, such as boiled chicken and rice. This allows your dog’s gastrointestinal tract to rest.

If the symptoms do not clear after a few days, or if your dog develops additional signs, return to the veterinarian immediately. Otherwise, the gastroenteritis should clear on its own, and no further examinations will be necessary. Most dogs recover fully from gastroenteritis, barring complications that may arise from severe dehydration.