Stories from My Diary-rrhea (part V): Chronic Small Intestinal Diarrhea

by Dr. Laci, aka, Dr. Poop

Chronic small intestinal diarrhea is diarrhea that has been present continuously or intermittently for 2-4 weeks and hasn't responded to therapies. Some of the causes discussed under acute small intestinal diarrhea will slide into this category inevitably, if not diagnosed properly and treated.

Of all the four categories I am discussing, this one is the poozie.  

The possibilities and different causes seem far more  endless, but I will do my best to make the chronic small intestinal diarrhea, well, end.

Small intestinal diarrhea results in a larger amount of poop passed with a mild increase in frequency. It does not result in straining during defecation, and affected dogs will commonly lose weight, often vomit, and have increased gas.  Blood in the stool will be darker or black, as it will be digested.

History, physical exam, medications the dog is receiving, and previous GI surgeries are all important.

Learning if the dog is suffering from a systemic problem, such as liver disease or even herniated spinal cord discs are all possible causes of chronic small intestinal diarrhea. 

As with all diarrhea, how healthy or ill the pet is determines how aggressively initial tests are conducted.

Weight loss often accompanies chronic small intestinal diarrhea.

In the case of dogs with weight loss, oily grayish feces (steattorhea--feces with excess fat that really stink), ravenous appetite, it is necessary to learn why they are not getting the nutrition they need.

This is separated into inappropriate digestion (maldigestion), protein-losing diseases (protein-losing enteropathy/PLE) and inappropriate absorption without protein loss (malabsorptive disease).  Your vet will perform diagnostic tests to rule these conditions in or out.

Exocrine pancreatic insufficiency (EPI) is the most common cause of maldigestion in dogs.  

It can affect any dog, but we see it most often in young German shepherds.  Biopsy either by endoscope or exploratory surgery may be needed to accurate diagnose many diseases and conditions.
PLE is a syndrome, not a singular disease, and has several causes:  obstruction, toxins, inflammation, infections, and cancer (seen all too often).  

IBD (discussed under chronic large bowel diarrhea), neoplasia, and lymphangiectasia (abnormal dilation of lymph vessels causing the loss of proteins and nutrients) are are commonly seen causes.  With PLE, a protein called albumin may be lost in the diarrhea.  Albumin normally helps keep water in the blood vessels of your dog, similar to a sponge, but when it is lost in the stool, water starts to leak out of the blood vessels and into other places that gravity takes it, like the legs and the underside of your pet's abdomen and chest cavity.

If enough protein is lost, the pet may develop edema (fluid accumulation) of the legs or belly--as if they weren't uncomfortable enough being hungry constantly and having chronic diarrhea.

Two huge causes of malabsorptive diseases are small intestinal bacterial overgrowth syndrome and dietary intolerance.

Unlike the large intestine which is rich with bacteria, the small intestine has significantly less bacterial organisms. When there is an overgrowth of bacteria, digestion is altered, malabsorption occurs, and diarrhea results.

Biopsy is required for a definitive diagnosis, but oftentimes trial therapy with antibiotic therapy is effective.  There are advantages and disadvantages to both approaches and you will need to decide which approach you want to choose with the help of your veterinarian.  I will discuss dietary intolerance in a future post.
Back to the big picture, chronic small intestinal diarrhea is often very difficult to diagnose.
Though many causes can be diagnosed with simple tests, invasive diagnostics may be necessary.  In veterinary medicine, this usually means heavy sedation, if not full anesthesia, which understandably frightens many pet owners.
It is important to remember though that chronic diarrhea is not normal or healthy.  

Small intestinal diarrhea means your pet is continuously losing nutrition. Imagine living in a state of continual ravenous hunger; if your pet suffers from small intestinal chronic diarrhea and is wasting away, this is what they are living with!  Try to imagine this and hopefully you will pursue the cause and solution more seriously.

Over time, chronic small intestinal diarrhea can have dangerous consequences, even if the cause of the diarrhea itself is not deadly.

If your dog is unfortunate enough to suffer from chronic small intestinal diarrhea, it may end up being one of those times you wish you had pet insurance. And tile floors.

Related articles:
A Tale of Many Tails—and What Came Out From Underneath Stories from My Diary-rrhea (part I)
Stories from My Diary-rrhea (part II): Acute Small Intestinal Diarrhea 
Stories from My Diary-rrhea (part III): Acute Large Intestinal Diarrhea (Acute Colitis)
Stories from My Diary-rrhea (part IV): Chronic Large Intestinal Diarrhea
Where There Is Smoke, There Is Fire: A Symptom Is Your Friend, Treat It With Respect!
The House Is On Fire! Bridget's Pancreatitis
Help! My Dog Is Purple!
It's Your Dog's Health

Laci Schaible has always been an animal lover and wanted to be a veterinarian since the third grade. Eager to actualize her dreams, she left home and started college with a full scholarship at the age of 16. She graduated with honors at the age of 19, and then became one of the youngest U.S. trained veterinarians in history when she graduated with her D.V.M. at the age of 23 from Texas A&M University.

After practicing as an associate at an emergency / referral and general practice small animal hospital, she was anxious to lead and manage her own hospital, which she successfully did for years. Performing surgeries with her husband Jed (also a vet) is one of her favorite aspects of practice.

Together, after losing their beloved family dog Madison to terminal cancer, Laci and Jed realized the need for pet owners to have affordable unbiased guidance for their pet's health care beyond their veterinarian with office hours. 

Jed's entrepreneurial genes and Laci's creative passion motivated them to fill this need, and was born.  Check out their blog for a mix of pet health advice, funny stories from the vet perspective, and even cool video blogs from Dr. Jed!

You can also follow Dr. Laci on Twitter  or VetLive on Twitter  or Facebook.