Dog diarrhea can be an acute condition, in which case it begins quickly and doesn't last long, or it can be a chronic condition, in which case it is a long-term problem, whether continual or recurring. Acute dog diarrhea is usually caused by the dog eating items that are indigestible. It can also be caused by a sudden change to the dog's typical diet or by food allergies. Chronic diarrhea is often caused by gastrointestinal parasites in a dog and is sometimes a symptom of underlying disease.
Dogs often suffer from acute diarrhea when they eat material they can't digest. The diarrhea results from the dog's system trying to clean itself out. Dogs are carnivores and scavengers by nature, and they sometimes eat items like dead animals, garbage, sticks or plastic. Such indigestible material irritates the dog's system and travels swiftly through the gastrointestinal tract, causing canine diarrhea.
Care should be exercised when feeding dogs. Sudden changes to a dog's diet can result in acute diarrhea, as can feeding it table scraps that aggravate the dog's gastrointestinal system. An improper diet is a major culprit in dog diarrhea, as dogs need to eat a well-balanced diet that is comprised largely of meat and vegetables. When trying a new dog food, dog owners should introduce the food to their pet gradually to minimize digestive disturbances and to make sure the dog can tolerate the food. Rarely, food allergies can cause dog diarrhea.
A major cause of chronic diarrhea is gastrointestinal parasites. Common parasites that bring on diarrhea in dogs include roundworms, whipworms and hookworms. Dog diarrhea is also sometimes caused by giardia, a protozoan parasite that affects the digestive system. Dogs can become infected with giardia by drinking untreated water. If the diarrhea is chronic and the dog has no parasites, it might be suffering from a disease such as irritable bowel syndrome, inflammatory bowel disorder or diseases of the kidneys, liver or thyroid.
Sometimes dog diarrhea is the result of medications. Antibiotics can cause diarrhea in dogs, as can deworming medicines and nonsteroidal anti-inflammatory drugs (NSAIDs). Dog diarrhea can also be caused by a dog's emotional state. If a dog is stressed or if it must adjust to sudden changes in its living situation or environment, it might suffer from acute diarrhea. A dog should always be taken to the veterinarian if it is feverish or dehydrated, or if blood is present in its stool.