Inflammatory bowel disease in dogs continues to be one of the most challenging conditions for veterinarians to treat. The cure for this painful, chronic gastrointestinal condition remains elusive, but a treatment plan that combines the synthetic steroid budesonide with a novel protein or hydrolyzed diet is generating support among leading veterinary specialists in the internal and nutritional fields.
Dogs suffering from IBD may demonstrate such signs as chronic or recurring vomiting, loose stools, loss of appetite, lethargy, low-grade fever, poor-quality hair coat and weight loss—signs that can be present in other medical conditions, making diagnosing IBD trickier. These dogs typically have inflammation of the stomach lining, colon and small intestine. Their immune systems are waging war on the invasion of bacterial, food or parasitic antigens. They are miserable and in pain, and their owners are often frustrated by the lack of a quick diagnosis and recovery.
"We still don’t know much about this condition, but we’re finding better ways to treat it,” says Joseph Wakshlag, DVM, Ph.D, associate professor of clinical nutrition at the Cornell University College of Veterinary Medicine in Ithaca, N.Y. "We tend to identify IBD by ruling out other possible causes, such as parasites and cancers. We back our way into diagnosing IBD.”
The primary types of IBD affecting dogs include:
Lymphocytic-plasmacytic enterocolitis. Considered the most common type of IBD, it is identified through a biopsy that confirms excessive numbers of lymphocytes and plasma cells on the colon wall or small intestine.
Eosinophilic enterocolitis: This challenging type of IBD is identified by the presence of eosinophils (small, rod-shaped white blood cells in bone marrow that control allergic and inflammatory responses) present in a dog’s colon, small intestine or stomach.
Granulomatous enteritis: A biopsy is needed to identify this rare type of IBD and rule out other possible medical conditions, such as histoplasmosis or fungal disease. This type is characterized by inflammation that triggers a narrowing of the small bowel.
Frederick Drazner, DVM, Dipl. ACVIM, co-chief of Wright Animal Hospital/Animal Specialty Services of Cook County in Des Plaines, Ill., says it is vital for veterinarians to confirm IBD by taking a detailed medical history.
"A detailed history is imperative to find out the frequency, consistency and character of the bowel movement,” he says. "Ask the client, ‘How long have the symptoms been going on? What therapeutic/dietary measures have been used in the past? What does the dog eat?’”
Pinpointing IBD as the cause also requires performing an extensive physical examination and conducting a series of diagnostic tests that may include:
* A fecal exam for the possible presence of a parasitic or bacterial agent
* Abdominal X-rays and possibly, an ultrasound
* A complete blood cell count
* Serum chemistry screen
But his favorite diagnostic tool is the endoscope.
Dr. Drazner has performed more than 800 endoscopic procedures on animals under general anesthesia. The scope, connected to a light source, camera and computer monitor, permits a veterinarian to collect biopsy samples and examine the condition of a dog’s colon, stomach or small intestine to detect any swelling, bleeding or presence of ulcers or foreign bodies.
"My advice is to practice, practice, practice performing fiber optic examinations,” Drazner says. "The endoscopic equipment has vastly improved in recent years. Gastroscopic, endoscopic and colonoscopic investigation by an experienced, skilled operator can yield invaluable histopathologic information with minimal stress to the patient.”
Once IBD has been diagnosed, Wakshlag favors gradually switching a dog’s diet, if the main proteins have been common ones such as beef, chicken or lamb. The dog would be then fed a novel protein or hydrolyzed diet. The veterinarian works with the client to introduce a specific protein the dog has never consumed, such as bison, kangaroo or rabbit.
| Breeds at Risk for IBD
Any dog of any age can develop inflammatory bowel disease; however, certain breeds are at a greater risk, with the Norwegian Lundehunds especially vulnerable, according to Joseph Wakshlag, DVM, Ph.D., assistant professor of clinical nutrition at Cornell University’s College of Veterinary Medicine.
Also on the at-risk list are:
* English bulldogs
* German shepherds
* Irish setters
* Wheaten terriers
Change of Diet
A second option is to go with a hydrolyzed protein diet. These are marketed directly to veterinarians and consist of minuscule protein particles that are too small to be detected—or to generate response from a dog’s immune system.
The goal with the nutritional approach is to calm the immune system that has been working overtime to combat allergens, and to give the inflamed, painful GI tract time to heal.
"People often try the novel food approach first because it is easy,” Wakshlag says. "If you put your dog on a novel protein or hydrolyzed diet and things get better, then the challenge is to gradually re-introduce the old foods, one at a time. When the diarrhea and vomiting return, you’ve figured out the problem.”
In some cases, cyclosporine, an immunosuppressant designed to reduce inflammation in the digestive tract, and azathioprine, a drug that suppresses lymphocytes invading the GI tract, are prescribed. Anti-nausea medications and antacids may also be warranted.
Wakshlag says prednisone has been the synthetic steroid of choice to protect a dog’s intestinal lining, ease digestive upset and restore a healthy appetite in affected dogs. It is relatively inexpensive, but he believes that Budesonide, given as a topical, yields fewer side effects.
"At Cornell, we often get the most severe cases of dogs with IBD,” he says. "We need to bring out aggressive doses of heavy-hitting drugs to combat IBD. Dogs with IBD feel miserable, but with the right treatment plan, most can experience a livable outcome.”
In the future, Drazner believes that immunosuppressant agents such as CellCept will be more widely utilized to combat IBD in dogs.
"Gene therapy will be the future of handling a lot of chronic, auto-immune diseases like IBD, diabetes and arthritis,” Drazner says. "CellCept is the main drug used on human patients with organ transplants. I have used it on four dogs—a golden retriever, springer spaniel, Brittany spaniel and a Yorkshire terrier, and it has improved their quality of life.
"But one must be very careful in using CellCept because it is very potent. Some veterinarians are turning to CellCept for dogs with IBD who don’t respond to prednisone, azathioprine or cyclosporine.”