Causes of Diarrhea in Dogs

Dogs are known to eat just about anything. Whether it’s a strange bug that crawled through the vents or some little treasures found in the cat’s litter box, dogs will see it as a Michelin star meal. Your dog’s curiosity can sometimes get them into trouble.

Even though some dogs will eat some questionable or even gross things, that doesn’t mean they can digest all those things. Just because something can be ingested, does not mean it can be broken down in the digestive tract, and this can end up triggering a stomachache, or worse. Unfortunately, our furry friends can’t tell the difference between healthy and unhealthy, and they end up eating things that cause discomfort or even hurt them in the long run. If your dog is experiencing diarrhea for a short time, do not worry. This is a common symptom that inflicts all dogs at some point of their lives.

Diarrhea in dogs can be caused by many things, such as eating spoiled food from the garbage, ingesting something while outside, a parasite, bacteria, a food intolerance, or eating some type of human food not intended for dogs. In minor cases, all they will need is a few days eating bland diet, lots of water, or perhaps a change to a new diet of wholesome and nutritious dog food to be as good as new. If symptoms persist more than a day or two, you may want to take them to the vet for further examination.

Watch for drastic changes in your dog’s behavior. It is normal for a dog to refuse to eat or sleep more while they are experiencing digestive upset. However, if your dog is extremely lethargic, difficulty standing or walking, dull vital signs, or refusal to drink water, you should immediately contact your veterinarian. Your vet may require a recent stool sample, so be prepared to collect a fresh sample for analysis.

This article is intended to be a guide on the causes, signs, and treatment of diarrhea in dogs so you can be a more informed owner for your furry companion.

Understanding the Digestive Tract

To figure out what is causing your canine to have diarrhea, it’s important to understand a dog’s digestive system and the three stages of digestion.

Stage 1: Ingestion

The teeth, tongue, saliva, and esophagus all play a role in the ingestion phase. Teeth tear and break up food into smaller chunks that are easily digestible, and saliva coats the food to make it easier to swallow. Unlike in humans where saliva starts to break down food, dogs’ digestion begins in the stomach. This is why they scarf down their meals without taking a breath. Since kibble is already broken down into small chunks, they don’t really have to chew.

Stage 2: Digestion and Absorption

There are three major players in the role of digesting and absorbing food.

  • Stomach – Food travels down the esophagus into the stomach where stomach acid, enzymes, and mucus all work to break down compounds into their constituent parts. Once this is ready to be absorbed, it has to pass through the pyloric sphincter in order to enter the small intestine.
  • Pyloric Sphincter – The pyloric sphincter acts as a valve that controls the flow of food past the stomach. If the food eaten is unable to be digested, and the dog’s body recognizes it as poisonous, the pyloric sphincter will remain closed and the dog will throw up the food before it reaches the small intestine. If the food can be digested but isn’t healthy for the dog, it will pass through the pyloric sphincter and result in diarrhea.
  • Small Intestine – Here is where most of the absorption process takes place. Though considered the “small” intestine, it is the largest organ in the body. To give you a picture, a medium-sized dog will have a small intestine with the surface area of a typical living room floor.
  • Other organs involved – The liver, kidney, and gallbladder also aid the flow of digestion by regulating blood hormone levels and producing bile (the natural chemical that gives feces its color).

Stage 3: Elimination

Once the chyme (mixture of gastric juices and digested food) passes into the large intestine, water and nutrients are absorbed before being eliminated from the body. If during the absorption phase the small intestine was irritated for any reason, this will result in the chyme passing quickly through the system and eliminating as diarrhea.

Often the discoloration of diarrhea is due to this quick release. There isn’t enough time to absorb the necessary nutrients and water, and the bile didn’t have a chance to coat the chyme.

Four Primary Causes

While diet and digestion are important factors that lead to the majority of diarrhea cases, it’s not the only factor. In fact, there are four different causes of diarrhea in dogs. Those causes include:

  • Change in diet
  • Infectious disease and parasites
  • Scavenging
  • Stress

Each one has a different set of symptoms that you can look out for and a different treatment method. Always visit with a veterinarian before you start unorthodox “home” treatments.

Change in Diet

Making a change in your dog’s diet can cause a bout of diarrhea if done incorrectly. Switching to a new food source, regardless of how similar or healthy the switch may be, can cause your dog to vomit or have diarrhea if you make a hard switch overnight. That’s why it’s crucial to change your dog’s diet gradually over a period of time.

Most dieticians recommend mixing an additional 10-20% of new food into the diet each day. To avoid diarrhea in dogs, diet changes should happen over the course of a week, or for especially sensitive stomachs, a month.

You might be wondering why change your dog’s diet at all? There are times in a dog’s life where a change may be necessary.

  • New Adoption or Puppy– Whether you adopt a dog from a shelter or get a new puppy, it is important to give them the very best nutrition. Shelter pets often endured a stressful environment, and may be undernourished. Start them off with a quality diet to help them build and repair muscles, and feed their gut to strengthen their immune system. For puppies, during the first twelve to eighteen months their brains are developing, muscles are strengthening, and bones are expanding. To sustain this, puppies need the best possible quality nutrients to support their development.
  • Older, “senior citizen” dogs – Throughout your dog’s life it is important to feed a high quality diet. However if you previously fed one of those grocery store brands, and now you are more informed of better options, what better time to help your older dog become stronger as they age. Common health issues in senior dogs can include skin issues, vision problems, brain function deterioration, joint pain, and a weakened immune system. Feeding a high quality food that improves gut health can go a long way for healthy aging. Your dog’s gut is the to a strong immune system to help fight disease. Senior dogs in particular can benefit from a healthy gut and a robust immune system.
  • Chronic diarrhea or vomiting – If your dog is experiencing chronic upset stomachs, it might be time to change their diet. New dietary restrictions can happen at any point in a dog’s life, which means despite feeding them the same thing for years, there could still be an issue with their food. If you assume that your dog is suffering from canine inflammatory bowel disease or has a food intolerance, it may be time to make a switch to their diet. Diets with a variety of quality, healthy fibers will help improve their digestive system. Look for foods with pumpkin as well, which is known for helping to improve digestion.

Foods That Don’t Agree With Dogs

There are certain “human” food items that can be toxic or send your dog into a diarrhea frenzy. Many people make the mistake of thinking dogs can eat anything that a person can, but this is not true. Of course your dog may want to eat these but that does not mean they should, or that it wouldn’t be unsafe for them. Some common foods that should never be fed to your dog include:

  • Fatty meats like bacon
  • Garlic and onions
  • Dairy products (especially ones that are sweetened)
  • Raw meat
  • Sugary foods
  • Grapes and raisins
  • Chocolate, coffee, caffeine
  • Alcohol

Superfoods for Dogs

What are Superfoods and are they safe for dogs? Well there are plenty of “superfoods” that are helpful to a dog’s digestion. Those superfoods include pumpkin, salmon, quinoa, and sweet potatoes. Pumpkin is rich in fiber and water-content and clears the digestive tract for dogs. Salmon provides healthy omega-3 fatty acids for a shiny, supple coat. Quinoa is high quality, digestible seed rich in protein, containing essential amino acids. And sweet potatoes are dense in vitamin A and C, which help boost the heart and immune system. Look for pet foods that contain these types of ingredients to aid their digestion and promote good gut health.

Diarrhea in Dogs What to Feed Them?

If your dog is experiencing diarrhea, their stomach is going to be extra sensitive for a while. The first step is to limit the diarrhea. Determining the cause can be difficult, so it is very important to observe their behavior to look for signs of  more serious condition. Usually diarrhea can be managed by feeding your dog a bland diet of boiled chicken and plain rice or plain quinoa for a day or two. You can also mix in a few tablespoons of plain, canned pumpkin (not the pie filling version). Always be sure your dog has access to fresh, clean water. You may notice that your dog will not want to eat for a day when their tummy is upset. Usually diarrhea will begin to clear up in a day or two, but they will still have soft poop. Gradually transition them back to their kibble, and mix in a small amount of the pumpkin or small amount of rice to help bind their stool. This would also be a good opportunity to check the brand of food you are feeding normally. Check the label…does it contain superfoods like pumpkin, quinoa, or sweet potatoes? Does it feature a healthy blend of quality fiber sources to support digestive health? Look for a food that has gut health as a benefit. This will help your dog maintain a healthier digestive tract overtime.

Lucy Pet food, for example, focuses entirely on Gut Health. Their duck and potato limited ingredients formula for dogs and chicken, brown rice and pumpkin limited ingredient diet formulas are ideal for dogs with food sensitivities. They also offer other formulas such as salmon, pumpkin and quinoa packed with superfoods and healthy fibers.

Infectious Diseases and Parasites

Sometimes diarrhea is a symptom of a more serious, severe condition; for example your dog might be suffering from an infection or parasite. These can only be treated by the care of a veterinarian and will require a stool sample or possibly blood test.

  • Bacterial Infection – The most common form of bacterial infection in dogs is known as leptospirosis. This infection typically comes from drinking stagnant water contaminated with these bacteria. If your dog is experiencing diarrhea and other symptoms like lethargy, fever, and vomiting, be sure to take your dog to the vet immediately.
  • Viral Infections – Most viral infections can be ruled out by vaccinating your dog at a young age. Otherwise, the canine parvovirus (or CPV) is a common virus in puppies aged six weeks to six months. This infection can be found in the intestines of dogs and can cause vomiting, diarrhea, and weight loss.
  • Parasites – A particularly nasty affliction for dogs, parasites can live inside their intestines.