What is diarrhea?
Diarrhea is unformed or loose stools, usually occurring in larger amounts and/or more often. Diarrhea is not a disease but rather a sign of many different diseases. Diarrhea associated with minor conditions can often be resolved quickly with simple treatments.
“Diarrhea may be the result of serious or life-threatening illnesses.”
However, diarrhea may be the result of serious or life-threatening illnesses such as organ system failure or cancer. Even diarrhea caused by mild illnesses may become serious if treatment is not begun early enough to prevent severe dehydration and electrolyte imbalance.
What causes diarrhea?
Diarrhea is the result of faster movement of fecal material through the intestine, combined with decreased absorption of water, nutrients, and electrolytes. If the main sign of illness in your dog is diarrhea, a relatively simple problem such as an intestinal infection from bacteria, viruses, coccidia, or intestinal worms may be the cause. In dogs, dietary indiscretion (eating garbage or other offensive or irritating materials), or a change in diet is a common cause of acute (sudden) diarrhea. Stress, especially following travel, boarding, or other changes in environment, can also cause acute diarrhea.
However, diarrhea can also be a sign of a more serious underlying disorder such as allergies, bacterial or viral infections, inflammatory intestinal disease, organ dysfunction, or other systemic illness.
How serious is diarrhea in dogs?
The seriousness of diarrhea depends on how long the diarrhea has persisted and how many other signs accompanies the diarrhea. If your dog has severe bloody diarrhea, or is showing more generalized signs of illness such as weakness, fever, vomiting, abdominal pain, or loss of appetite, or if dehydration accompanies the diarrhea, the cause may be more serious. For example, diarrhea is one of the first signs seen in parvovirus, a viral infection that can cause life-threatening illness in susceptible dogs.
How is the cause of diarrhea determined?
The nature of the diarrhea, such as its color, consistency, smell and frequency, are important in helping determine the cause. Your veterinarian will usually ask you to bring a representative sample of fresh fecal material with you to your appointment. You may also be asked to provide answers to a series of questions.
If diarrhea is the only sign, a minimum number of tests are performed to rule out certain parasites and infections. If diarrhea is severe or associated with several other clinical signs, your veterinarian will perform a series of tests in order to reach a diagnosis and to determine how sick your dog has become as a consequence of the diarrhea. These tests enable your veterinarian to treat your dog appropriately.
Diagnostic tests may include microscopic fecal evaluation, X-rays with or without barium (a liquid given to dogs that shows up on X-rays and can highlight abnormalities in the intestine), blood tests, fecal cultures or DNA tests, biopsies of the intestinal tract, endoscopy, ultrasound, and exploratory abdominal surgery.
What is the treatment for diarrhea?
Once the diagnosis is known, specific treatment will be tailored to the underlying problem and may involve medication or dietary treatment.
For healthy adult dogs with simple acute diarrhea, your veterinarian may initially recommend a conservative approach rather than an in-depth diagnostic work-up. Conservative treatment may involve withholding all food for 12-24 hours or feeding small amounts of an easily digested diet at more frequent intervals. Water should be offered at all times. The recommended diet is often a veterinary prescribed diet designed to be easy to digest, while also containing ingredients such as prebiotic fiber that helps the intestinal tract recover from what triggered the diarrhea. A home-cooked bland diet may also be recommended by your veterinarian that often contains a combination of cooked rice or pasta and boiled chicken. This may be more tempting to your dog initially, but is not generally as therapeutic as the veterinary diet. This conservative medical approach allows the body’s healing mechanisms to correct the problem. As the stools return to normal, you can gradually reintroduce your dog’s regular food by mixing it in with the special diet for several days.
Antidiarrheal agents, dewormers and or probiotics (bacteria that support intestinal health) may be prescribed in some cases. Metronidazole (brand name Flagyl®) and tylosin (brand name Tylan®) are commonly prescribed anti-diarrheal agents that decrease the intestinal inflammation that often leads to diarrhea. Dewormers commonly used include Panacur®, Drontal®, and Dolpac®. There are some probiotics and supplements that can be very helpful for dogs experiencing diarrhea. As the quality and effectiveness of probiotics and supplements are not always known, it is always recommended to ask your veterinarian before giving your dog anything of this nature.
If your pet is not improving within two to four days, further tests or more aggressive treatment may be necessary. Severe or prolonged diarrhea can result in significant dehydration and metabolic disturbances due to fluid loss and your pet may require hospitalization for intravenous fluid therapy or other, more intensive, treatments.
In all cases, if your dog does not improve within two to four days, a change in medication or further tests may be necessary.
What is the prognosis?
The prognosis depends upon the severity of the diarrhea, as well as the specific diagnosis and the dog’s response to treatment. Most cases of simple diarrhea will make a full recovery, while dogs with chronic diarrhea may require dietary management or medication to keep the condition under control.