What causes diarrhea?
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, like cancer. Even diarrhea caused by mild illnesses may become fatal if treatment to prevent severe fluid and nutrient loss is not started soon enough.
How serious is diarrhea in dogs?
Severity depends on 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:
  • Vomiting
  • Dehydration
  • Loss of appetite
  • Abdominal pain
  • High fever
  • Lethargy
  • 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, a series of tests may be performed. These diagnostic tests 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, diets or surgery.
If your dog does not appear systemically ill from diarrhea, the cause may be less serious. Some 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 minimal 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 or relieve inflammation in the intestinal tract, as well as a restricted diet for a few days. This approach allows the body's healing mechanisms to correct the problem.
We expect to see improvement within two to four days. If this does not occur, a change in medication or further tests may be performed to better understand the problem.
See Feline Diarrhea