The Scoop on Your Dog’s Poop: 3 Common Causes for Diarrhea in Dogs

Many dog owners show their pets their love by sharing their dinner, or giving them too many treats. However, introducing new foods or too many rich treats into your dog’s diet can lead to gastrointestinal (GI) problems like diarrhea—which is, in fact, one of the most common reasons pet owners take their dog to the veterinarian. Diarrhea is a symptom of an underlying problem, and has numerous causes, many of which are preventable. Our Staples Mill Animal Hospital describes common causes for dog diarrhea, and treatment options to relieve your dog’s discomfort.

#1: Food-related diarrhea in dogs

Like people, some dogs may seem to have an iron stomach, eating anything and everything they can find, without any GI problems. However, your dog’s digestive system functions differently from a human’s, and most dogs are sensitive to sudden dietary changes. Dietary indiscretion—also known as “garbage gut”—describes a GI upset when your dog eats something they cannot tolerate, such as table scraps, garbage, or new treats suddenly introduced to their diet. Your dog’s signs will be similar to food poisoning in people, such as lethargy, diarrhea, and vomiting. Some dogs may experience mild diarrhea after a dietary indiscretion that quickly resolves, but some will develop severe diarrhea, or pancreatitis, a painful, inflammatory condition that can be life-threatening. Other food-related dog diarrhea causes include:

  • Pet-toxic food — Many human foods, including grapes, chocolate, and onions, are toxic to pets. Always check the ASPCA Animal Poison Control Center (APCC) list, before offering any human food to your dog.
  • Food allergies — Like people, some pets are sensitive to certain ingredients, such as protein in chicken, that can cause diarrhea. Pets often have allergies to multiple food types, and our Staples Mill Veterinary Hospital veterinarian may recommend a novel protein diet if they suspect your dog has certain food allergies. However, never change your pet’s diet without consulting our veterinarian.
  • Sudden diet change — Many pet owners want to feed their pet expensive, boutique diets, but these designer foods are usually grain-free, which has been linked to heart and GI problems in pets. Additionally, never change your pet’s diet suddenly, but rather transition them to the new food gradually, always under our veterinarian’s direction.
#2: Infectious causes of diarrhea in dogs

Dogs, especially young puppies, are at risk for a variety of infections that can affect their GI tract and lead to diarrhea, which can be life-threatening in severe cases. Regular veterinary examinations and preventive care are vital to ensure your dog is protected from common dog infectious diseases. Most puppies are born with a pot belly from intestinal parasites passed in utero from their mother. Roundworms, hookworms, whipworms, and tapeworms, which can be passed from infected feces, are common culprits for diarrhea in dogs. Dogs with intestinal parasites are at risk for anemia and other nutritional deficiencies, which can lead to a poor hair coat, lethargy, and vomiting in severe cases. Other common infectious causes for diarrhea include:

  • Protozoan parasites — Giardia and coccidia are single-celled organisms that are considered opportunistic invaders of a dog’s GI tract. These organisms do not always cause problems, but dogs who are immunocompromised, stressed, or have other medical problems are at risk from protozoal-induced diarrhea. Giardia is commonly found in standing water, grass, or infected feces, so prevent your dog from drinking any standing water when outdoors.
  • Viral diseases — Canine parvovirus (CPV) and canine distemper virus are common viral diseases that can lead to diarrhea. Young puppies are most at risk, because their immune systems are not fully developed, but older, non-vaccinated dogs are also at risk. Bloody stool is often the first CPV sign. Fortunately, vaccinations are available to prevent these life-threatening viral diseases.
  • Bacterial infections — Like people, dogs are at risk from bacteria-induced diarrhea when they ingest contaminated food or infected feces. Some bacteria, like Salmonella or Campylobacter spp., may also infect people.
Regular veterinary examinations and preventive care are vital to ensure your dog is protected from these common infectious diseases.

#3: Stress-related diarrhea in dogs

Most pets, like people, thrive on a regular routine, and changes in your dog’s environment or routine, or meeting new people can lead to stress-induced colitis, or diarrhea. Dogs who are regularly anxious, or have other anxiety disorders like noise aversion, are at increased risk for stress-related diarrhea.

Feces commonly contain small amounts of blood, because straining and inflammation can cause breakage of blood vessels in the lower GI tract. However, if your dog has large amounts of blood in their stool, or jam-colored blood, they need immediate veterinary care. If our veterinary team rules out medical causes for your dog’s diarrhea, we may recommend behavioral modification and calming medications for your dog during stressful situations.

Diagnosing and treating diarrhea in your dog

Bring your dog who has diarrhea for a veterinary examination as soon as possible, and also bring a fresh sample of their feces to be checked for intestinal parasites. Our Staples Mill Animal Hospital veterinarian will perform a nose-to-tail examination, as well as other diagnostic tests that may include a parvo test, a fecal bacterial test, allergy testing, and blood work, to check for inflammation or underlying medical problems. We may recommend advanced imaging, such as X-rays or ultrasound for an in-depth examination of your dog’s GI tract, and to check for any ingested foreign material. Treatment will depend on the underlying diarrhea cause and severity, and may include:

  • Antibiotic medication
  • Deworming medication, and monthly parasite prevention medication
  • Anti-nausea medication
  • Pain medication
  • Probiotics
  • Anti-anxiety medication
  • Specialized diet
  • Intravenous (IV) or subcutaneous fluids, to treat dehydration
Make an appointment with our Staples Mill Animal Hospital team if your dog has diarrhea, and especially if they have blood in their feces, so we can alleviate their discomfort and help prevent future GI problems.