Defined in its simplest terms, diarrhea is when there is too much water in the feces. There are many different reasons this can occur including:

In the case of over eating, the intestines become over full with food particles which do not allow the intestines to produce enough enzymes to break it down. With changes in food, the stomach and intestines are not given a proper period of adjustment, creating the inability to produce the proper enzymes for the new food. With stress as the factor, the dos stomach becomes upset, causing an extreme fluctuation in the type and amount of enzymes produced. All three of these situations compel the intestines to hold onto the food particles which then in turn hold on to water which the intestines can not absorb.

If a dog has an infection or has eaten food from the trash, excess water can be present in the intestines which results in diarrhea. This situation can also be caused by intestinal parasites, E. coli and Salmonella.

For many dogs, diarrhea is caused by over eating, stress, eating from the trash and intestinal parasites and in many cases does not cause severe illness. However, diarrhea can be the result of a serious systemic illness and in this case should be taken to a veterinarian immediately.

Visiting the Veterinarian

Many dogs with simple diarrhea may not need a trip to the veterinarian. If a dog has mild diarrhea that is not making it uncomfortable, has no other symptoms, and does not otherwise feel bad, it is OK to wait 24-36 hours to see a veterinarian. Many cases of simple diarrhea will resolve on its own. If a dog has diarrhea and seems uncomfortable, if the diarrhea appears bloody or like tar, if the dog has other symptoms, or seems sick, then it is wise to see the veterinarian right away. Even if the diarrhea does not go away any faster after the veterinary visit, the veterinarian can evaluate the dog and make sure nothing more serious is going on and can give medication to make the dog more comfortable.

After the veterinarian examines the patient, he or she will want a fresh stool sample. If your dog has recently (in the last 30-45 minutes) had a bowel movement, you can collect that and take it with you. If not, the veterinarian can collect a sample in the office. Several things will be done with the stool sample. These include:

A fecal flotation to check for intestinal parasites

A direct fecal smear to check for red blood cells, white blood cells and abnormal or unusual bacteria.

A fecal smear with abnormal bacteria (the ones that look like tennis racquets)

If your dog has diarrhea combined with vomiting, bloody stool and acts very ill and has been this way for several days, the veterinarian will want to take blood and x-rays to see if some other systemic illness is causing the diarrhea.

Heather Fox is an experience veterinarian and passionate teacher on Clivir.com where you can find more of her lessons about Dog Atopic Dermatitis Causes and Dog Parvovirus Symptoms.