Diarrhea is not a disease; rather, it is a symptom of many different diseases. Many mild cases of diarrhea can be resolved quickly with simple treatments. Others are the result of fatal 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. 
Unless you're absolutely sure diarrhea is caused by eating something wrong - not harmful - , I advise you to see the vet immediately. 

Diarrhea caused by digestive upset may be cured by feeding the dog chicken and rice. Kaospectate is a drug to treat diarrhea caused by digestive upset. 

Also read our article about Giardia, a parasite that lives in the bowel and causes severe diarrhea. 

How serious is diarrhea in dogs? 
  

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

1. Vomiting 

2. Dehydration 

3. Loss of appetite 

4. Abdominal pain 

5. High fever 

6. Lethargy 

7. Bloody and/or watery diarrhea 
  

What types of tests are performed to find the cause? 
  

If diarrhea is associated with several of the above signs, we perform a series of tests in the hope that a diagnosis can be made. This permits more specific treatment. Diagnostic tests may include radiography (x-rays) with or without barium, blood tests, stool cultures, biopsies of the intestinal tract, and exploratory abdominal surgery. Once the diagnosis is known, treatment may include special medications and/or 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 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. We expect improvement within 2-4 days; if this does not occur, a change in medication or further tests are done to better understand the problem. Please keep us informed of lack of expected improvement so that we may manage the situation properly. 
  
  

1. How long has the diarrhea been present? 
  

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

3. Circle the letter of each item that applies: 
  

Consistency 

a. Watery stool 

b. Stool is the thickness of pancake batter 
  

Blood 

a. Very bloody stool 

b. Only sporadic blood present 

c. Blood not present in stool 

d. Bright red blood present 

e. Dark, tarry blood present 
  

Degree/Frequency 

a. Entire stool is soft or watery 

b. Only portions of the stool are soft or watery 

c. Diarrhea with each bowel movement 

d. Diarrhea is sporadic (some bowel movements are normal) 

e. Only 1 or 2 bowel movements per day 

f. More than 4 bowel movements per day 
  

Color 

a. Stool is dark brown in color 

b. Stool is very pale in color 

c. Stool is black and tarry in appearance 
  

Miscellaneous 

a. Thick mucus or pieces of tissue present in stool 

b. Loss of bowel control (defecates in the house on the floor) 

c. Severe straining when having a bowel movement 
  

Is your dog's appetite normal? If not, is it eating at all? 
  

What have you been feeding your dog during the last week? (Include dog or cat foods, treats, table foods, milk, and anything else that it gets on a daily basis. Also state what percentage of the diet is each item or category.) 
  

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

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

Is your dog as active as normal? 
  

Describe any change in water consumption (up or down). 
  

Has vomiting been occurring? If so, how frequently and for how long? 
  

Does your dog go outside your house? 
  

Does your dog go outside your yard? 
  

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

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

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

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

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