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Canine Diarrhea

What causes diarrhea?

Diarrhea is not a disease but a symptom of many different diseases. Many mild cases of diarrhea can be resolved quickly with simple treatments. Others are the result of serious or life-threatening illnesses such as cancer. Even diarrhea caused by mild illnesses may become fatal if treatment is not begun early enough to prevent severe fluid and nutrient losses.

How serious is diarrhea in dogs?

Your veterinarian will attempt to determine how sick your dog has become as a consequence of the diarrhea. When the dog is systemically ill (when more than one body system is involved), some of the following may be noted:

  • Vomiting
  • Dehydration
  • Loss of appetite
  • Abdominal pain
  • Fever
  • Lethargy
  • Bloody and/or watery diarrhea

What types of tests are performed to find the cause of my dog’s diarrhea?

If diarrhea is associated with several of the above signs, your veterinarian will perform a series of tests in order to make a diagnosis. This permits specific disease treatment. Diagnostic tests may include microscopic fecal evaluation, abdominal radiography (x-rays) with or without barium, blood tests, fecal cultures, biopsies of the intestinal tract, video endoscopy, ultrasound and exploratory abdominal surgery. Once the diagnosis is known, treatment may include special medications, diets, or surgery.

If your dog does not appear systemically ill from diarrhea, the cause may be less serious. Some of the minor causes of diarrhea include stomach or intestinal viruses, intestinal parasites, and dietary indiscretions (such as a change in diet or eating garbage or other offensive or irritating materials). A minimum number of tests are performed to rule out certain parasites and infections. These cases may be treated with drugs to control the motility of the intestinal tract, drugs that relieve inflammation in the intestinal tract, and, often, a special diet for a few days. This approach allows the body's healing mechanisms to correct the problem. If your pet is not improving within two to four days, a change in medication or further tests may be necessary It is important to keep your veterinary clinic updated about your pet’s progress to optimize its recovery.


1.  How long has the diarrhea been present?

2.  Is the diarrhea more severe now than a few days ago?

3.  Circle each item that applies:


  • Watery stool
  • Stool is the thickness of pancake batter


  • Very bloody stool
  • Only sporadic blood present
  • Blood not present in stool
  • Bright red blood present
  • Dark, tarry blood present


  • Entire stool is soft or watery
  • Only portions of the stool are soft or watery
  • Diarrhea with each bowel movement
  • Diarrhea is sporadic (some bowel movements are normal)
  • Only 1 or 2 bowel movements per day
  • More than 4 bowel movements per day


  • Increased, large amount of stool
  • Decreased or normal, small amounts of stool


  • Stool is dark brown in color
  • Stool is very pale in color
  • Stool is black and tarry in appearance


  • Thick mucus or pieces of tissue present in stool
  • Loss of bowel control (defecates in the house on the floor)
  • Severe straining when having a bowel movement

4.  Is your dog's appetite normal?  If not, are they eating at all?

5.  What have you been feeding your dog during the last week?  Include dog or cat foods, treats, table foods, milk, and anything else that you have fed your pet. Also state what percentage of the diet is each item or category.

6.  Does your dog have access to foods other than what you feed them?  If so, what?

7.  Has there been a diet change in the last few weeks?  If so, does that correspond with the onset of the diarrhea?

8.  Is your dog as active as normal?

9.  Describe any change in water consumption. (Increased or decreased)

10.  Has your pet vomited?  If so, how frequently and for how long?

11.  Does your dog go outside your house?

12.  Does your dog go outside your yard?

13.  Does your dog have access to garbage cans, either within your house or yard or outside your yard?

14.  Does your dog have toys that it plays with that it could have swallowed?

15.  Does your dog have access to sewing materials, such as thread or needles, rubber bands, or string?

16.  Do you have other dogs or cats that live with this one?  If so, does the other pet have diarrhea?

17.  Do any of the members of your family currently have a diarrhea problem?

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