Can My Dog Get Stomach Flu?

The short answer? No. But then, neither can you because influenza is a virus that primarily affects the respiratory tract, not the digestive system.

What we call stomach flu is usually something called gastroenteritis, and dogs can definitely get that. The only trick is that gastroenteritis isn’t a very specific term. Instead, it covers a range of symptoms (usually diarrhea and vomiting) that may have many different causes. Here’s what you need to know.

What Causes Gastroenteritis in Dogs?

Human gastroenteritis has many different causes, and the same is true for the canine version. Some of the things that can cause what we know as “stomach flu” in dogs are:

• Tumors
• Obstructions or foreign bodies
• Poisoning
• Thyroid disease
• Serious infections, including meningitis, pneumonia and UTIs
• Intussusception, which is when the intestine telescopes on itself
• Pancreatic issues
• Bacteria, such as E. coli or salmonella
• Parvovirus
• Distemper
• Certain types of fungal infection
• Parasites, including many varieties of worms

That’s not a complete list, either. In fact, it’s just a small sample of what can cause gastroenteritis symptoms in your dog.

Not all the causes of diarrhea or vomiting are serious, though. Sometimes, it’s something as simple as a sudden diet change that requires a few days of adjustment.

Is Gastroenteritis Dangerous for Dogs?

There’s no simple answer to that question either. It can be, and if the underlying cause is one of the more serious ones on this list, it could even be a medical emergency.

Generally, if your dog doesn’t stop vomiting or having diarrhea, or there’s blood in their vomit or stools, you should not wait. Bloody gastroenteritis, or hemorrhagic enteritis, is nearly always a sign that emergency medical treatment is needed as soon as possible.

What Should I Do If My Dog Has Gastro?

Just like in humans, the biggest risk to dogs who have gastroenteritis is dehydration, which happens quickly and can be fatal if not treated.

Unfortunately, because dogs that have this condition might not be able to keep any fluids down, that can mean that your dog needs to go to the vet to be put on an IV, to replace the lost fluids.

If your dog has a single incident of a runny stool or vomits a little just once, it’s probably not gastroenteritis, but if they have frequent incidents of either in a short amount of time, along with these symptoms, you may need a veterinary diagnosis:

• Listlessness and lethargy
• Anorexia (refusing to eat) and weight loss
• Fluid loss
• Signs of dehydration, or being unable to keep fluids down
• Hemoconcentration, which is a shortage of plasma in the blood (only visible on blood work)
• Hypovolemic shock, which is shock caused by sudden drops in blood volume and circulation

If your dog displays any visible symptoms of these, get to the vet!

How Will Your Veterinarian Diagnose and Treat Canine Gastroenteritis?

The first step in treating gastroenteritis is usually to get the dog onto an IV if they are showing signs of dehydration. Since dehydration can kill dogs in a very short amount of time, this will buy your veterinarian some time to figure out what is going on, and to treat the underlying cause.

Diagnosis is also tricky because there are so many possible causes. There may be signs that point to a specific cause, in which case your veterinarian will focus on those first. If not, they may have to draw blood and take stool samples for lab analysis.

If the lab work doesn’t turn up anything that might be causing the problem, x-rays may be required to diagnose tumors, obstructions, or intussusception.

Once your veterinarian knows what has caused the problem, they will decide on treatment. This will be based on the underlying cause of the symptoms and could include medications for bacterial or fungal infections, surgery, or a variety of other treatments.

What Is the Prognosis for Canine Gastroenteritis?

There is no simple answer to this question. If the cause of the symptoms is relatively mild, and treatment is administered early on, there’s a good chance your dog will be fine.

If there is a more serious problem causing your dog’s distress, or if there’s a delay in treating certain diseases or conditions, then the prognosis looks a lot less positive.

The best way to give your dog the best chance of a full recovery is to pay attention to their condition, and if there’s any doubt whatsoever, or if symptoms continue for an hour or more, go to the vet. It’s far better to feel like a fool for taking a dog with a mild problem to the veterinary emergency room than it is to be heartbroken because you didn’t go soon enough.