As veterinary professionals, it’s one of the most common questions we hear: Why is my dog having diarrhea? Dog diarrhea can be caused by a wide variety of things and ranges from mild stomach upset to more serious conditions. Read on to learn more about this condition and what we can do to get your dog’s gut feeling normal again.
What Is Dog Diarrhea?
First things first, how do you know if your dog is having diarrhea? Diarrhea is not a disease, but a symptom of something causing your pup’s GI distress. It’s defined as passing loose or liquid stools in large amounts or more often than usual. Some mild cases resolve quickly, while others will require ongoing medical support.
In general, puppies, small dogs, and senior dogs are at higher risk of complications from diarrhea. If symptoms continue for a prolonged period, diarrhea can quickly lead to dehydration, electrolyte imbalance, and lethargy/weakness.
Common Causes of Dog Diarrhea
Diarrhea is extremely common in dogs. Most of our canine companions will experience a bout of diarrhea at least once in their lifetime. The most common causes include:
Dogs eating something they shouldn’t
Dogs explore the world with their mouths, and sometimes that gets them into trouble! The number one cause of mild diarrhea for dogs is eating something they shouldn’t (AKA dietary indiscretion). When dogs eat things like garbage, spoiled food, or non-food objects, it can easily cause stomach upset and diarrhea. With dietary indiscretion, most cases will resolve after 24-28 hours on a bland food diet.
If your dog doesn’t show improvement, symptoms worsen, or new symptoms develop (eg, vomiting, lethargy), call your veterinarian! Sometimes, when dogs eat non-food items, they can become lodged in the GI tract and cause a bowel obstruction, also known as a gastrointestinal blockage. If left untreated, bowel obstruction can be fatal.
Changing your dog’s food too quickly
People eat a wide variety of foods every day… so our dogs can too, right? Unfortunately, no! Your dog’s gut microbiome contains the specific bacteria and enzymes needed to break down the food they’re accustomed to. When you switch your dog’s diet, the gut microbiome needs time to “catch up.” That’s why we always recommend transitioning between diets gradually. Switching diets over the course of 7-10 days allows the gut to adjust and prevents dog diarrhea.
Follow this plan to help prevent stomach upset when switching your pet’s diet:
- Days 1–3: 75% old food, 25% new food
- Days 4–6: 50% old food, 50% new food
- Days 7–9: 25% old food, 75% new food
- Day 10+: 100% new food
Internal parasites or infection
Puppies and dogs that go to daycare, boarding facilities, and dog parks are most likely to have diarrhea caused by parasites or contagious diseases. Internal parasites that cause diarrhea include roundworms, hookworms, Giardia, or coccidia. Some of these parasites can be passed to humans, so it’s important to get your dog tested if they’re at high risk for parasites!
Stress or anxiety
Just like in people, stress and anxiety are often overlooked causes of GI upset. When dogs experience stress, they produce stress hormones that disrupt gut bacteria and speed up digestion. This can lead to soft, watery, or even mucusy stools. Common triggers of stress colitis (diarrhea caused by stress) include:
- Boarding or daycare
- Separation anxiety/being left alone
- Changes in household routine
- Loud noises, like fireworks
- Travel
If your dog has recurring bouts of diarrhea caused by stress, your veterinarian may recommend calming supplements, medication, or behavior training to help.
More Serious Causes of Dog Diarrhea
While diarrhea is common, it should always be taken seriously. Chronic or recurring diarrhea can be the first sign of several serious underlying health conditions.
Potential culprits include:
- Inflammatory Bowel Disease (IBD)
- Pancreatitis
- Liver or kidney disorders
- Chronic Hepatitis
- Addison’s disease
- Immune system conditions
- Certain cancers
Because many things can cause diarrhea, it’s important to determine the root cause before coming up with a treatment plan. Depending on your dog’s other symptoms, your veterinarian may recommend lab work, X-ray or ultrasound imaging, or a fecal exam to rule out parasites and bacterial infection.
Diarrhea in Puppies
Puppies are especially susceptible to two major, life-threatening illnesses: parvovirus and distemper. In addition to diarrhea, puppies with these illnesses will likely experience loss of appetite, persistent vomiting, and extreme lethargy. You may also see bloody stool, fever, or abnormally low body temperature.
Both parvovirus and distemper are highly contagious, life-threatening diseases that require immediate intervention! If you see any of the above signs in your young puppy, contact your veterinarian as soon as possible!
Treatment for Dog with Diarrhea
As we mentioned, diarrhea is a symptom, not a disease. If your dog is having chronic or recurrent diarrhea, it’s important to determine the cause and not just treat the symptom.
For mild cases, your veterinarian may recommend withholding food for a short period (usually 12 hours) to allow the gut to settle. After that, offer small amounts of bland food until your pet’s stools return to normal frequency and consistency, generally 24-28 hours.
If your dog is showing signs of dehydration (dry or sticky gums, thick saliva, and sunken eyes), they might need hydration support. Subcutaneous or IV fluid therapy can help prevent dehydration and electrolyte imbalance.
If your dog’s diarrhea continues for over 48 hours or is accompanied by other symptoms, call your vet to see if they need to be seen. Our team can help triage over the phone and work with you to come up with a plan.
Compassionate Veterinary Care for Your Best Friend
At Pine Point Animal Hospital, we’re proud to offer comprehensive veterinary care. Whether your pet just needs a little extra R&R or ongoing support and monitoring, we can help!