Inflammatory Bowel Disease (IBD) in Dogs

IBD in dogs, or inflammatory bowel disease, is a syndrome caused by chronic irritation and inflammation of the gastrointestinal (GI) tract. This inflammation can interfere with your dog’s ability to digest food and absorb nutrients.

Although IBD cannot be cured, treatment and long-term management can help control symptoms and improve your dog’s quality of life.

What Is IBD in Dogs?

IBD in dogs, or inflammatory bowel disease, is a syndrome caused by chronic irritation and inflammation of the intestinal tract. It can stem from multiple factors, including a single underlying disease or a combination of diseases.

Whatever the cause, the result is inflammation within the gastrointestinal (GI) tract. Often coupled with a defective immune system, this inflammation leads to a greater allergic response triggering more inflammation, pain, and thickening of the GI tract.

Over time, this results in an inability to digest and absorb nutrients properly. 

Regardless of its cause or causes, IBD significantly impacts your dog’s quality of life and should not be ignored.

IBD can affect any part of the GI tract, including the stomach, small intestine, large intestine, or any combination.

IBD should not be confused with IBS (irritable bowel syndrome); IBS is a disease that affects the intestinal muscles, specifically those of the large intestine, and causes constipation and diarrhea in dogs. Fortunately, IBS in dogs is extremely rare.

What Are the Symptoms of IBD in Dogs?

Symptoms of IBD in dogs include vomiting, diarrhea, and poor appetite. These symptoms may occur intermittently over several weeks.

Common symptoms include:

• Vomiting
• Diarrhea
• Poor appetite
• Excess gas
• Melena (black tarry stools)

If left untreated, these symptoms will lead to poor absorption of nutrients, weight loss, abdominal distension, swelling of the extremities, and, in extreme cases, blood clots, which are often fatal.

What Causes IBD in Dogs?

The underlying cause of IBD in dogs is often unknown, but several factors may contribute to inflammation of the GI tract and trigger an immune response.

Conditions often associated with IBD include:

• Parasitism, often seen with Giardia
• Bacterial infections and other infectious agents
• Dysbiosis, the alteration of normal bacterial populations within the GI tract
• Food allergy or sensitivity
• Overactive or exaggerated immune response (often termed “autoimmune”)

Additionally, genetic factors may be a consideration, as some breeds such as Yorkshire Terriers, German Shepherds, and Boxers, are predisposed to the condition.

How Veterinarians Diagnose IBD in Dogs

Veterinarians diagnose IBD in dogs through a physical examination, laboratory testing, imaging, and intestinal biopsies. While bloodwork, urinalysis, X-rays, and ultrasound can support a diagnosis, intestinal biopsy is considered the gold standard.

Intestinal Biopsy for IBD in Dogs

As the gold standard, biopsy can be performed via endoscopy, colonoscopy, or exploratory surgery. However, because biopsy can be cost-prohibitive and is invasive, in many cases IBD is presumed.

Diagnostic Findings and Additional Tests

Supportive information gathered from the above tests may show signs of:

• Anemia (low red blood cell count), due to chronic blood loss or inflammation
• Low proteins (albumin, cholesterol)
• Increased liver enzymes (ALT, ALP)
• Gas and fluid distended intestinal segments
• Increased thickness of the intestinal walls

Additional tests your veterinarian may recommend include a stool exam for cases of parasitism, blood tests to help determine absorption ability, and an ACTH stimulation test to rule out Addison’s disease (adrenal insufficiency).

How Veterinarians Treat IBD in Dogs

IBD in dogs has no cure, but it can be controlled and managed with medications, dietary changes, and other supportive treatments. It's important to follow your veterinarian's guidelines throughout treatment to help manage your dog's symptoms and well-being.

Medications for IBD in Dogs

Anti-inflammatories and immunosuppressives are the mainstay of treatment, with prednisone, budesonide, and azathioprine being the most commonly prescribed. 

These medications are not without risks. It’s important to discuss the side effects with your veterinarian and to not discontinue their use without your veterinarian’s recommendation.

Dietary Management for Dogs With IBD

Additionally, as food sensitivity is an important factor in IBD, your veterinarian will most likely prescribe a change of diet. 

This may entail a novel protein diet (consisting of less commonly used sources of protein, such as fish, duck, rabbit, venison, or kangaroo) or a hydrolyzed diet, where the protein is chemically broken into pieces so small that the immune system is less likely to react. In some cases, this may be effective as the sole therapy.

Additional Treatments for IBD in Dogs

Given the limitations of stool exams, deworming and an antibiotic trial may also be recommended. Recent studies have shown that probiotics and prebiotics are beneficial in restoring and maintaining GI health and help promote the growth of good bacteria.

What if a Dog With IBD Isn’t Getting Better?

Even with the right combination and dose of medications, it is not uncommon for IBD treatment to take a while.

Be patient; it often takes several weeks to see improvement in your dog’s symptoms but working with your veterinarian and adhering to the re-check guidelines and lab tests will be key to tracking your dog’s response to treatment.

Recovery and Long-Term Management of IBD in Dogs

IBD in dogs is a lifelong condition with no cure, but ongoing treatment and veterinary monitoring can help manage symptoms.

Do not stop treatment without first consulting your veterinarian. Most likely, the drugs originally prescribed will be slowly tapered over the course of several weeks to months, to ensure that the lowest effective dose that controls symptoms and minimizes reactions is used.

Your dog’s prognosis will depend on the extent of the syndrome, with a lower chance of long-term recovery for pets with low protein levels.

Because the immune system is affected, caution should be taken with any medications or injections (such as vaccines) that could cause its stimulation, so be sure to discuss the inherent risks and benefits with your veterinarian prior to administration.