Ron Hines DVM PhD
What is Inflammatory Bowel Disease ?
Inflammatory bowel disease (IBD) is a catch-all term. It is used to describe many conditions with similar signs but different causes. It can be quite confusing to owners and veterinarians alike because IBD is also called, Chronic Colitis, Colitis, Irritable Bowel Syndrome, Lymphocytic-plasmacytic Inflammatory Bowel Disease, Regional Enteritis, Granulomatous Enteritis or Spastic Bowel Syndrome depending on what symptoms predominate. Basically, any time your dogs intestine remains irritated over long periods of time, some form of IBD is present. The signs of intestinal parasites can be similar to IBD. The classification is too complicated for anyone to agree on. This always happens when several poorly understood diseases cause similar signs. If you got to this page and you are uncertain if your pet has IBD, go here.
To further confuse matters, Irritable Bowel Syndrome in dogs, a stress-caused problem in dogs with similar signs to IBD , is often confused with IBD.
Occasional intestinal and stomach disorders are very common in dogs . Most cases are caused by eating things your pet shouldn't - like spoiled foods, spicy treats, or trashcan waste. These usually cause a big mess and then correct themselves in a matter of days. But dogs with IBD have loose stools and diarrhea day after day.
In all forms of IBD, defense cells, accumulate in the walls of your pet's digestive system. Sometimes this occurs because the pet is consuming things that do not agree with it or shouldn't have been eaten. But just as frequently or more so, it is just that the pet's body defenses have gotten out of whack and are mistakenly attacking compounds in the intestine that are really not a threat to the dog.
What Happens In Inflammatory Bowel Disease ?
When things irritate the lining of your pet's intestine, they cause food to move through it faster. With time, this irritation causes the lining to thicken and become inflamed. Blood and tissue cells that normally fight bacteria and other invaders, accumulate within the lining of the inflamed intestines causing cramping, pain, colic, diarrhea and distress. These fragile intestines are more likely to bleed and they allow unhealthy intestinal organisms to proliferate and displace the healthy ones. These changes also make it harder for your pet to absorb nutrients from its food. When the beginning portions of the intestine are involved, the pet may also vomit or loose its appetite. When the final portions of the intestine are involved, the stool is loose, frequent, watery and sticky with mucus. Bright blood is often present when the lower intestine is involved (colitis).
These problems can be occasional or continuous. When they are continuous, pets often loose weight. It is also common for dogs with this condition to eat or chew on unusual items (pica) and it can be difficult to decide if pica is the cause or result of the problem.
Flatulence is also a common problem and so is a dull hair coat and heavy shed. When the lower intestine or colon is inflamed, the pet may strain and defecate more frequent, mucous-covered, stools.
Some types of IBD are genetic and are associated with certain breeds. The lymphocytic/plasmacytic form is one of these. It is most common in German Shepherd and Shar Pei dogs. Basenjis have their own form of the disease called immuno-proliferative IBD. Boxers suffer from a form called histiocytic ulcerative colitis while Irish setters have a wheat gluten-sensitive form of the disease.
The second most common form of IBD is Eosinophilic IBD. It tends to be more severe than the lymphocytic form, but it often gets better when diet changes are made. Eosinophils are blood cells involved in allergies - so food allergies are a suspected cause.
What Are The Signs Of Inflammatory Bowel Disease ?
The most common complaint is persistent loose stools, straining and diarrhea leading to accidents in the house. This occurs because the intestine is moving too fast and not given time to remove enough water from the things your dog ate. Irritation of the colon and anus causes the straining. We all know what that is like.
Dogs with this problem can also vomit. Some veterinarians include conditions that cause stomach irritation and vomiting in the IBD complex. I prefer to call those conditions gastritis . When vomiting occurs with IBD, it is due to inflammation in the upper small intestine just below the stomach. It is possible for a pet to have both conditions simultaneously.
Certain things hint as to what portion of the digestive tract is most inflamed. When vomiting and infrequent, bulky loose stools and weight loss predominate, we tend to think of a problem high in the intestine. When frequent smaller stools, straining, blood or mucus-flecked stools occur, we tend to think of a problem lower down in the intestines. Most often, a bit of both is occurring but one predominates.
Dogs with the high form may run low fevers. The may also have secondary bacterial intestinal infections. In general, pets with the high form of IBD look more ill.
Is One Breed Of Dog More Susseptible To IBD Than Another ?
A 2012 study of dogs with this problem in the UK found that weimaraners, rottweilers, German shepherds, boxers and border collies had a greater risk of developing IBD. Of those breeds, border collies tended to develope the problem at the oldest age. You can read that study here .
WHAT CAUSES INFLAMMATORY BOWEL DISEASE ?
The most common form of IBD in dogs is the lymphocytic/plasmacytic form (LPIBD). This describes the type of cells that pathologists see when they examine biopsies from the pet's intestine. Some of these cells are always there, but it is abnormal when they are found in large numbers. Since we rarely find anything present that should have drawn these cells to the area, we currently consider it similar to a false fire alarm. IBR is a common disease in humans, and physicians are just as stumped. When we find better treatments for pets, it will come through research designed to help humans with similar problems.
The second most common form of IBD is the form where pathologists see mainly eosinphils in unusually high numbers in the intestinal wall. These cases of Eosinophilic Inflammatory Bowel Disease are probably caused by food allergies. They can also be called food hypersensitivities. These are the cases where changing the protein sources in your pet's diet helps most. Some dogs are not really allergic to food ingredients that bother them. It is their inability to digest or absorb certain nutrients (maldigestion-malabsorption) that leads to intestinal upset every time they are exposed to the ingredient(s). This is sometimes called mal-assimilation syndrome as well.
Chronic intestinal infections with bacteria, fungi or protozoa can also cause chronic diarrheas. Although pets get better when given the correct antibiotics, they often have an underlying intestinal problem that gave the organisms the opportunity to get out of control. However, salmonella and campylobacter infections can cause chronic IBD-like symptoms without underlying disease.
Granulomatous enteritis is another condition said to cause IBD in dogs. Granulomas are nodules of the body's defense cells that accumulate around infectious organisms or foreign particles within the body. It is a specific disease in horses, but it may not represent any specific disease of dogs.
Dogs, especially older dogs, sometimes develop tumors of the intestines. When these tumors involve large segments of the intestine, they can cause symptoms similar to IBD.
To further confuse you, Irritable Bowel Syndrome (IBS) is not the same as Inflammatory Bowel disease (IBD). IBS has many of the same symptoms. But in IBS, the intestines are hyperactive, not from irritation, but from excessive nerve stimulation. The stimulation is usually psychological and due to stress, fear or nervousness. It occurs in dogs and is similar to what occurs in humans.
How Would I Know If My Dog Has Inflammatory Bowel Disease ?
If you dog has loose stools , overly frequent stools, blood-containing stools, straining or diarrhea over more than 10 days, IBD needs to be considered as a possible cause. Persistent loose stools inflame the anus causing scooting that can be mistaken for anal sac disease. Straining to defecate can also be mistaken for constipation.
Inflamed intestines turn many pets into picky eaters with good and bad days. So poor appetite, weight loss and a lusterless, brittle coat often accompany IBD. Gurgling tummies (borborygmi), bloating and discomfort also occur. Sometimes, vomiting occurs as well.
The actual signs in your pet will depend on which part of it's intestine is most inflamed. If the upper intestine and stomach are most involved, vomiting and weight loss should be the first things you notice. If the middle intestine and colon are most involved, diarrhea, weight loss and less frequent or no vomiting would be more likely. If the upper intestines are most affected, the diarrhea is likely to be very watery ,large in volume and occurring only a few times a day. Upper intestinal IBD also causes the pet to appear more ill than the lower intestinal form. In the lower intestinal form, there is more straining and frequency and blood and mucus is more apparent on the stool.
Are The Other Conditions That Might Cause My Pet To Have Similar Signs ?
Yes. Some dogs have an idiosyncrasy about eating stuff they shouldn't. Chewing on sticks, eating leaves, excessive grooming, or getting into garbage day after day cause chronic loose stools than can not be distinguished from IBD. Sometimes owners know this is happening. But sometimes stool from these dogs need to be collected on various days and passed through a screen to identify offending material that is irritating their intestines.
Intestinal parasites such as whipworms and strongyloides can also cause loose stools and diarrhea that can not be distinguished from IBD. Repeated fecal checks are needed to find these parasites and often it is simpler to just worm the pet several times with medications that kill these parasites. Most veterinarians will also give these pets metronidazole (Flagyl) in case giardia parasites are part of the problem. However, giardia rarely cause chronic diarrhea in dogs unless an underlying intestinal problem is present.
Dogs with underlying liver or pancreatic disease can have signs similar to IBD. Your veterinarian may run some liver and pancreatic tests to rule this out.
What Would Make My Veterinarian Suspect This Condition ?
Inflammatory Bowel Disease will be high on your veterinarians diagnostic list as soon as you tell him/her the symptoms your pet is experiencing. Long-standing diarrhea with or without vomiting, weight loss and increased mucus in the stools (sometimes with streaks of blood) are all suggestive of IBD.
The vet will then suggest some tests to rule other causes out. The results of laboratory tests are not always clear cut, so it may take some time for the veterinarian to sort things out.
During the veterinarian's physical exam of your pet, he/she might feel thickened intestines and enlarged lymph nodes surrounding them. That is common in long-standing IBD.
The veterinarian may notice that your pet has lost weight or should weigh more than it does. Although IBD can affect any breed, vets know that they see it IBD more frequently in German Shepherds, Cockers, Yorkies, Wheatons, Rottweilers and Basenjis. If your pet is less than 2-3 yrs old, IBD might not be at the top of the vet's diagnostic picks. The mean age of dogs coming in with this problem is 6.3 years. But I suspect many have had mild or intermittent cases for years prior to that.
What Tests Will My Veterinarian Run ?
Generally, the vet will start with a fecal sample examination to rule out parasites and some blood work to rule out pancreatic, liver or other systemic disease as the cause.
In most cases of IBD, the blood work results are normal. If the problem is long standing and severe, your pets total blood protein level may be low due to its inability to absorb nutrients and leakage out through the intestinal wall. Occasionally it's globulin level will be elevated. If the pet has been vomiting persistently, its blood potassium level may be low. A few pets will have an increase in their WBC eosinophil numbers - a possible hint at a food sensitivity or parasitic problem.
When the results of those tests come back negative, most vets will try modifying your pet's diet and perhaps putting the pet on a medication like metronidazole (Flagyl). Flagyl kills giarida and several bacteria that cause diarrhea. But it also appears to somehow lessen diarrhea even when no parasites or invading bacteria are present.
The vet may give or suggest medications that slow, soothe and coat the intestines.
If diet modification and temporary medications solve the problem, your pet is very lucky. If not , other tests must be run.
Often an x-ray and abdominal ultrasound are next. However, they basically rule other causes out. The only test that gives a clear yes-no answer to an IBD diagnosis is an intestinal biopsy. This requires that your pet be anesthetized and that small snippets of tissue be removed from the pet's intestines, either surgically or through a tube (endoscope) inserted down your pet's throat and into it's intestines. Samples may also be taken from the other end - the way a colonoscopy is done on humans. The veterinarian will also visually check the lining of your pets intestines looking for damage.
Intestinal biopsy is an expensive procedure, often requiring a certified veterinary internist working from a veterinary specialty center. Not all pet owners have the money to pay for this service. If you do, have it done. If the biopsies show that your pet does not have IBD, the vet will keep searching for the cause. Cases of Intestinal lymphagectasia can be mistaken for IBD. Intestinal lymphagectasia also requires an intestinal biopsy for diagnosis.
If you can not afford endoscopy/biopsy for your dog and IBD is the most likely cause of your pet's problems, it is entirely plausible to request that your pet be treated with medications and diets that are used to control IBD to see how well they control the problem. This should only be done when the other likely causes of chronic diarrhea have been ruled out. A medication that is often included in an IBD treatment plan is prednisone. It can be quite helpful in controlling the inflammation caused by IBD. However, occasionally, this drug can also mask other problems, such as intestinal tumors (lymphoma). So you may wish to stop short of giving prednisone until you have a clearer diagnosis.
What Treatments Will Help My Pet ?
All the treatments for IBD try to decrease inflammation in the intestines. Some are aimed directly at the immune system itself, some at slowing down intestinal motility, some at coating and protecting the lining of the intestine and some at limiting specific diet ingredients that are irritating your pet's digestive system. None of these techniques will permanently cure your pet but they often help manage the problem.
Medications That Work Directly On Your Pet's Immune System
Corticosteroids (steroids, cortisone, etc.) are very effective in decreasing inflammation. The most commonly used corticosteroid is prenisone. It is very effective in lessening or eliminating the signs of IBD in dogs. However, prednisone can have a number of serious side effects. So it must only be used when absolutely necessary and in as small an amount as possible. The problem with giving too much prednisone is that it suppresses the immune system throughout the pet's body - not just in the intestinal tract. Prednisone, and drugs like it, also cause weight gain, fluid retention, liver changes and a number of other undesirable side effects if they are used too frequently and in too high an amount. Dexamethasone, prednisolone and all common corticosteroids have these same side effects.
A newer corticosteroid which shows promise in IBD is budesonide (Entocort® EC). This drug is marketed to treat Crohn's disease in people. Crohn's disease is also a form of IBD. Budesonide may cause less of the systemic side effects we associate with corticosteroid use.
Other medications that disable the immune system are also used. Two are cyclosporine and azathioprine. These are powerful anti-cancer medications. They must be managed carefully with frequent laboratory tests of your pets system. They have been known to cause pancreatitis, bone marrow and liver problems.
Sulfasalazine (5-ASA, Salazoprin, Azulfidine,etc.) is a sulfa antibiotic. However, it has an anti-inflammatory action inside your pet's intestine. Because it is poorly absorbed, it does not have the level of side effects that steroids do. So it is often tried in the treatment of IBD before resorting to cortiocosteroids. Sulfasalazine has occasionally affected the glands of the eyes that produce tears causing a permanent problem called dry eye or keratoconjunctivis sicca (KCS). Olsalazine and Mesalamine are similar drugs that might be less likely to cause KCS.
There are some studies that suggest that omega-3 fatty acids are helpful in decreasing intestinal inflammation in people with Crohn's disease. Since they are not toxic, there is no harm in trying them. Fish oil is a good source.
Medications That Slow Down Your Pet's Intestines and Stop Vomiting
Occasional use of loperamide (Imodium) or diphenoxylate (Lomotil) sometimes helps during flair-ups in dogs (do not use either of these medications in cats). But when they are given continuously over long periods of time they may loose their effectiveness or cause constipation. They are quite safe when the correct dose is given for your pet's size.
Medications That Protect The Lining Of Your Pet's Digestive System
Pepto Bismol (bismuth subsalicylate) helps some pets with IBD. It is particularly helpful when vomiting is part of the problem or during diarrhea flare-ups.
When inflammation is severe enough to cause bleeding ulcers of the lining of your pet's intestine, mistoprostol , cimetidine and ranitidine , which decrease stomach acidty, or sucralfate , which forms a protective barier against acidity, sometimes help.
Antibiotics That Sometimes Help
An antibiotic called metronidazole (Flagyl) often helps pets that have IBD. Metronidazole does not only kill harmful bacteria and protozoa that might be compounding your pets problem. Even when harmful bacteria are not the apparent root cause of your pets problem, metronidazole is sometimes effective. We do not know why.
Another antibiotic, tylosin, sometimes helps control IBD when it is added to your pet's food. A newer antibiotic, used with apparent success in treating IBD in humans, is rifaximin. It is mentioned in an article I reference again later (ref). I have no experience using it but others do. (ref)
What About Diet Changes And Special Diets ?
You should always try diet changes before resorting to medications to manage IBC. It is rare that diet changes alone will be enough. But limiting your pets food to the things that are easiest for it to handle will allow you to use less medication.
Many highly digestible, hypoallergenic and bland diets are commercially available or can be prepared at home .These diets should be free of preservatives, additives and coloring agents. They should either contain an unusual protein source such as cheese, rabbit, venison, cottage cheese or duck or contain proteins that are hydrolyzed into small non-antigenic component molecules (HA, z/d, etc.). It can take up to several months to see improvement.
Sometimes high fiber diets are helpful. Again, they are available commercially (OM, r/d etc). You can also add fiber to your current diet. See my home cooked recipe page for suggested sources of fiber. Increased fiber does not help all pets with IBD. Some do better when the fiber content of their diet is actually reduced.
Some dogs with IBD have less diarrhea when the fat content (or source) in their diet is reduced. High fiber diets, designed for pet to loose weight are also lower in fat.
Can My Dog Be Cured ?
Dealing with IBD in a pet requires a great deal of patience and dedication.
Occasionally, owners see the problem go away with, or without treatment. In these cases, the problems was probably not true IBD in the first place. In true IBD, we can control the problem, but we can not cure it. This is because the underlying biochemical defects that make your pet prone to the problem are not understood. But once you have worked out a special nutrition and life-style plan for your dog, it is a problem you both can live with. There will probably be flare ups when medications will be needed. In some pets, we see the best results when your give medications continuously.
New medications are always being tried. Generally, veterinarians read about them in articles aimed at controlling Crohn's disease in people and give them a try in dogs. Because IBD symptoms in dogs have natural peaks and valleys, it can be difficult to quickly decide if any given medication really helps.
Over time, fibrous tissue builds up in the walls of your pet's intestine and other changes occur that make it harder for the pet to absorb nutrients and, perhaps, to keep weight on. You can compensate for this with and extra-nutritious diet and supplemental vitamins.
Because there is often an underlying genetic element in this disease, breeding your pet will perpetuate the problem in future puppy generations. So it is not conscientious to do that.
Can Recent Discoveries In Humans With Chronic Intestinal Inflammations Help My Dog ?
Microbiota transplantation (FMT)
Perhaps.
Physicians are coming to realize that the vast number of micro organisms that naturally live in the large intestine have a tremendous influence on general health. Most dogs with IBR or similar conditions have received antibiotics on various occasions. Those antibiotics invariably change the species of bacteria and other beneficial organisms (gut flora) that live in your pet's intestine. Not only are the species of bacteria important, what portion of the pet's intestine they live in is important too. Administering certain medications, such as antacids, have the potential to may higher portions of the pet's intestine available for undesirable colonization by these organisms. (ref) It is possible that those flora changes will not return to what they were prior to antibiotic therapy and that those changes might have a negative impact on your pet's intestinal health. Your veterinarian may attempt to correct the problem with probiotic pastes. However, those pastes, at best, restore only a small fraction of the species that were lost. Their effect is minimal and short-lived. The best way to attempt to restore your pets bacterial flora is through a process called microbiota transplantation (FMT) , in which a complete, healthy bacterial population is transferred by high enema from a healthy pet to your pet. This concept is a new one for most small animal veterinarians. These links will take you to two recent key articles on the subject ( link 1, link 2)
