Diagnosing and treating chronic diarrhea in dogs can be a difficult and arduous task. There are many potential causes and isolating that problem can take time and effort, however it can be vital for your dogs overall health to correctly manage chronic diarrhea.
As opposed to acute cases of diarrhea, where intestinal upset occurs suddenly and with treatment will resolve within several days, chronic diarrhea has a pattern of occurring over weeks or even months. Chronic diarrhea in dogs is considered when there is a change in the frequency, consistency and volume of fecal material for more than three weeks. Such occurrences may have an episodic pattern, where the stool may become firm for a period, then become soft and unformed again, without any obvious cause.
The most common symptom of chronic diarrhea in dogs is diarrhea of varying severities. Chronic diarrhea in dogs can be broken down into two main categories- diseases of the small bowel, and diseases of the large bowel.
Symptoms of small bowel intestinal disease:
- Larger volume of feces than normal
- Dogs will pass feces more frequently than normal (2-4 times a day)
- Weight loss
- Feces may appear darker than normal, or tar colored
- Dogs may have excessive gas
- Dogs may also have episodes of vomiting
Symptoms of large bowel intestinal disease:
- Smaller volume of feces than normal
- Dog will pass feces significantly frequently than normal (4 or more times a day)
- Dogs will strain to defecate, appearing urgent
- Feces may appear to contain flecks of blood
- Feces may contain mucous
Veterinary care is necessary for any dog suffering from chronic diarrhea. Based on your dogs symptoms and physical exam, your veterinarian may recommend various tests to help determine the underlying cause of the intestinal disease.
Some common causes of small bowel intestinal disease in dogs include:
Inflammatory bowel disease (IBD)- In affected dogs, the intestine is taken over by inflammatory cells, eventually leading to scar tissue throughout the lining of the digestive system. Dogs with this condition often have a bad hair coat, due to poor absorption of nutrients. Diagnosis of IBD can be difficult to confirm. Treatment is aimed at reducing the inflammation, as well as dietary changes to provide a more easily digestible food source.
Parasite infection, such as that of Giardia, can be a source of chronic and acute diarrhea dogs. Fecal examination and antigen testing can diagnose the presence of intestinal parasites, and treatment is generally curative in these cases.
Bacterial infection, such as Salmonella or Clostridium perfringens, often cause severe chronic diarrhea. Fecal cultures can be used to diagnose the presence of these bacteria, and long-term treatment can be utilized to treat and prevent reoccurrence.
Dietary sensitivity, in the form of food allergies and intolerances can occur in dogs. Similar to lactose intolerance in people, dogs may have or develop allergies or sensitivities to variety of ingredients in dog food, leading to chronic inflammation in the intestinal tract. Treatment is aimed at identifying the causative ingredient(s) in the food, and identifying a diet that does not cause sensitivity.
Liver disease can cause chronic diarrhea in dogs, and is often an early symptom present before diagnosis is made.
Pancreatitis, or inflammation of the pancreas, can occur acutely (such as dogs who get into the trash) or on a chronic level. The pancreatic gland is responsible for secreting hormones such as insulin and glucagons into the bloodstream to regulate blood sugar levels, as well as making the digestive enzymes that break down food for digestion. Pancreatitis causes these digestive enzymes to decrease, and in severe cases the enzymes may begin to digest the actual organs of the dog instead of digesta. Diarrhea, abdominal pain, vomiting and a poor appetite are the symptoms of pancreatitis, but because these symptoms are shared with so many other gastrointestinal problems, it can be hard to diagnose.
Hypoadrenocorticism, or Addisons disease is an endocrine disorder caused by decreased amounts of cortisol produced by the body to combat stress. Chronic diarrhea, in addition to lethargy, vomiting, anorexia, weight loss, increased thirst and urination, as well as a breed predisposition can indicate Addisons disease.
Many causes of large bowel intestinal disease are the same as those in small bowel disease, such as parasite infections, bacterial infections and Addisons disease. In addition, other causes of large bowel diarrhea include:
Dietary changes that occur too quickly can cause acute and chronic diarrhea. Making food changes gradually, over a course of 7-10 days can help to prevent this problem.
Poorly digestible or high-fat diets can cause chronic diarrhea, as the body struggles to rid itself of materials it cannot make use of. In the case of high-fat diets, Pancreatitis can occur if these diets are given over long periods of time.
Lymphosarcoma is a malignant form of cancer that most often affects the lymph nodes and hepatobiliary, gastrointestinal or respiratory symptoms. Dogs with gastrointestinal lymphosarcoma typically have weight loss, lethargy, vomiting, diarrhea and abdominal discomfort, and may have concurrent illness in other body systems.
In any case of chronic diarrhea in dogs, a veterinarian will first perform a physical exam on the dog and in conjunction with clinical signs and history, recommend testing. Fecal examinations in the form of a fecal flotation or fecal cytology may be performed to determine parasite or bacterial infection. A complete blood count and blood chemistry analysis may be performed to determine the overall health of the dog, as well as indicating signs of liver disease, pancreatitis, lymphosarcoma and Addisons disease.
Abdominal radiographs may be performed to rule out an intestinal obstruction or masses in the abdomen or spleen as a cause of chronic diarrhea.
If no obvious cause of the diarrhea can be determined, an abdominal ultrasound may be recommended to assess if the bowel walls appear thickened (indicating inflammatory bowel disease) and to do a further check for an intestinal mass, foreign body as well as evaluate the condition and function of the intestinal tract.
Treatment and success rates are highly dependent on the underlying cause of diarrhea. It is highly important to determine the cause for chronic diarrhea in dogs, as the treatment will vary greatly depending on the cause. In some cases total resolution of symptoms may not be possible, but with proper medical management, may become well controlled and manageable.