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Top Six Causes Of Diarrhea In Dogs

Diarrhea is one of the most common reasons for visits to our office.  As a symptom, it is uncomfortable and potentially dangerous for your dog, and it’s unpleasant for an owner to deal with as well.

There are so many causes of diarrhea, some life threatening and some less serious, and diagnostics are usually required to determine the root cause.  Therefore, if your dog has more than one or two episodes of diarrhea, if his diarrhea is extremely watery, if he is also lethargic and vomiting, or his stools are black and tarry, he needs to be seen.

Here are six common causes of diarrhea in dogs.

Intestinal parasites are common in dogs and cats and can cause a variety of symptoms, including watery or bloody diarrhea, vomiting, anemia and poor general health. Intestinal parasites can be spread to other animals and some organisms are infectious in people as well.  Many animals infested with parasites will not have symptoms, so yearly fecal testing is important for prevention.  In dogs with diarrhea, testing for parasites and treatment with antiparasitics is one of our top concerns.

Read More About Intestinal Parasites:
Whipworm Infection In Dogs
The Connection Between Tapeworms And Fleas
Roundworms In Dogs: Causes, Risks And Prevention
The Vampire Within: Hookworm Infection
Everything You Ever Wanted To Know About Giardia (And Some Stuff You Didn’t!)

Some dogs are what we call garbage disposal dogs: they can eat anything and everything and suffer no ill effects.  Other dogs are more sensitive to dietary changes, especially if what they have eaten is human food, or if they have eaten something excessively fatty (like gravy) or sugary (like pies or other baked goods).  Changes in regular diet should also be done gradually, mixing the new food with the old food, reducing the proportion of the old food each day. Finally, dogs that eat non food items, such as toys, clothing or even rocks, can develop diarrhea from trauma to the GI tract or if the item becomes lodged.  If your dog has diarrhea and you suspect he ate something he shouldn’t have, he needs to be seen.

Read More About Dietary Indiscretion
Not On The Menu: 10 Foods That Dogs Cannot Eat
Your Dog Ate What? Why Pets Eat Non-Food Items
Gas And The Embarrassing Dog: 8 Causes Of Flatulence In Your Canine Friend
FAQ’s About Fecal Testing

A dog taking antibiotics for a urinary tract infection or other bacterial problem can develop diarrhea.  The flora of the gut is delicately balanced and antibiotic use can kill off plenty of beneficial bacteria as well as the organism causing the problem, resulting in stomach upset and diarrhea.  As a preventive, you should never give antibiotics without your vet’s approval.  Unless otherwise noted, antibiotics should be given with food.  Consider adding a probiotic to your pet’s diet while he is taking antibiotics.  Probiotics contain healthy bacteria that can help maintain the proper conditions in your dog’s GI tract.

The pancreas is a glandular organ with two functions: it secretes hormones to regulate sugar metabolism and it secretes digestive enzymes to help break down food. When a dog has pancreatitis, digestive enzymes are released improperly, causing pain and inflammation. Pancreatitis has the potential to be life threatening. The cause of this painful condition isn’t always known, but it can be triggered by eating an excessively fatty meal.  Miniature schnauzers are genetically predisposed to pancreatitis. The classical signs are poor appetite, vomiting and diarrhea, painful abdomen and fever. Pancreatitis is a serious condition, but also responds well to treatment, so it is important to seek an exam and diagnosis if your dog has any of the signs of pancreatitis.

In dogs, the organ affected most by stress is the colon.  A stressed canine body, be it from a medical problem, or something like household changes or noise phobia or a new puppy, pulls water out of the lumen and into the colon.  At the same time this is happening, the regular muscular motion of the GI tract that moves food through increases, resulting in diarrhea.  An occasional bout of stress diarrhea is usually nothing to worry about, but if your dog has more than a few episodes, he should be seen.  Dehydration can happen quickly, especially in small dogs.

Tumors in or around the intestinal tract can cause diarrhea. If your pet’s belly seems bloated or painful along with chronic diarrhea, he should be checked for cancer.

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