Inflammatory Bowel Disease Part 3

Posted by Aaron

Friday, March 5, 2010

So what do I do if an owner can only do items one, two, and three on my diagnostic list? We treat presumptively. Then we rely on response to therapy to try and dial in on a diagnosis.

Maybe we change to a hypoallergenic diet. I'm a fan of the Royal Canin Hypoallergenic, but the novel protein diets like Venison and Potato are great ideas. They also have a product called Intestinal HE which can be fantastic for some chronic mal-digestion cases or during the healing phase of a severe gastroenteritis. It's a rich food, so it's not appropriate for long-term use in patients where obesity is an issue.

Maybe we treat with a broad spectrum de-wormer. Maybe we use an antimicrobial (like metronidazole) to help get bacterial populations under control. Maybe we use a pro-biotic or pre-biotic. Maybe we are able to get good enough response with these treatments and we can stop there.

Or maybe we don't.

If we want the answers then we move to the next step. Don't shy away from biopsy just because it sounds scary. It really is critical to making a good diagnosis.

Steroid use is something that should be considered ONLY after we have have ruled out as much as we can or as much as we can afford. Steroid trials can be a great diagnostic tool, but we have to keep in mind that LOTS of stuff will respond to steroids. Just because there is inflammation that responds to steroid doesn't mean that we know what has triggered it. Wouldn't we feel silly if we treat with a steroid and get a response only to find out later that the cat has hookwork infection or giardia and we just never did a proper exam to find that out!

Another unfortunately common error is to send a dog for colonoscopy for chronic large bowel diarrhea only to find out that there are whipworms causing the problem and we did a poor job or properly diagnosing them or failing to treat them. Don't jump ahead. Follow the advice of your veterinarian, work stepwise. If your veterinarian asks you to submit yet another sample of stool don't respond with, "If you didn't find it before, I'm not paying for you to not find it again." Remember that it often times takes multiple attempts to find a parasite. It's a ton cheaper to do another fecal exam and treat with fenbendazole (Panacur) than it is to jump to endoscopy.

Fire off questions to me. This is a long topic and I've hopefully not made it too confusing. I'd love to hear questions if there's something that doesn't make sense.


Inflammatory Bowel Disease part 2

Posted by Aaron

Thursday, March 4, 2010

Here's how I approach a case of chronic vomiting or diarrhea and what would be required to answer ALL possible answers. Think through this list when you go to your veterinarian (starting at item one - don't skip ahead) and it can help aid in the diagnosis tremendously - ESPECIALLY the historical findings.
  1. First things first - a good history. When does the diarrhea and vomiting happen? Is there any kind of temporal connection? Travel? Diet change? What about weight loss or gain? Is the vomiting immediately after a meal? First thing in the morning on an empty stomach? Is the diarrhea characterized by sudden urgency or constant straining? Did the vomiting or diarrhea respond to previous treatments? If so, what treatments and in what way did it respond? Did the problem resolve and then recur, or did it only resolve while ON the medications? What other medications is the patient on? What foods do the other animals in the house eat? Does this pet eat the other pet's food (either before it's eaten or after it's pooped out - IOW is your dog a poo-eater?)? Is your pet also having urinary problems? What breed(s) is your pet? All of these things help narrow down the list of likely suspects.
  2. Physical exam. Weight gain? Weight loss? How does the abdomen feel on palpation? Is the pet dehydrated? How does the patient "as a whole" look? Does the patient have other diagnosed problems that could be causing this problem? Are there any lumps or bumps that would cause concern? How does the anus and rectum feel on examination? Is there lots of gas? Constipation?
  3. Examine the poo. As was said on one of the funniest episodes of the sitcom Scrubs, "If you want to know what's wrong with you, it all comes down to Number 2!" Seriously, though, the poo can tell us a lot. This would be the best way for us to identify most parasites. Not all parasites can be found at all times, and fecal exams are never 100% sensitive. Repeat fecal exams at different times and on GOOD SIZED samples is critical. I get totally chapped when I see people take these little, itty, bitty, tiny samples and then declare that "the fecal is negative." NO NO NO. You must take a good sized sample, use good technique in your fecal examination, and then you can declare that "no parasites were seen." Seems like I'm splitting gnat weenie hairs, but it's a big distinction. No whipworms today doesn't mean much. They're a booger to find on a good day. Most would agree that you need a total of 5 fecals done on 5 different days to say that there are no whips present. Many times, submitting the stool to the lab for advanced diagnostics is smart. The labs can now look for parasite DNA in many cases and this makes the test very sensitive. You still have to submit a LARGE ENOUGH sample. You want to know how to make your veterinarian's job easier and help get a proper diagnosis? Bring stool with you! Fresh, stinky, warm poo makes me happy to see. Now I've got a big sample and I don't have to go fishing for it. It drives me crazy when someone come in with a complaint of stool problems, but then doesn't bring a sample.
  4. Basic blood workup. Look at my previous post on this one. We're looking for things like increased eosinophils (allergic reaction), low albumin (loss of protein), changes in cholesterol (poor absorption), abnormal lipids (funky fat absorption) and such.
  5. Gastrointestinal specific bloods include things like a "pancreatitis test" also known as a Spec cPL, Trypsin Like Immunoactivity (TLI), cobalamine, and thiamine. These each help identify if there is evidence of chronic mal-absorption and tell us more about if the pancreas is functioning normally.
  6. Endoscopy or abdominal exploratory surgery. The idea here is that we may need to LOOK at the gut and take biopsies to get a diagnosis. Endoscopy/colonoscopy is where we drive a camera down or up (depending on the end you start at :) ) and it allows you to see the lining of the gut. You can look for ulcerations, polyps, thickening, and any number of abnormalities. You can also use a little biopsy tool to take a tiny piece of the lining of the gut. The major benefits of endoscopy are 1) You get to see the inside of the gut up close and personal, 2) you don't have to open up the abdomen, and 3) it gives you nice biopsy samples that are only partial thickness - there's less of a defect to heal. The major downsides are 1) you can only get SO far down or up before you just can't get any farther with the camera. This means that there are large lengths of bowel you can't see. You will, therefore, totally miss problems if they are segmental and the segment that's a problem is out of reach. 2) the biopsy taken is only partial thickness. This means that you miss some of the deeper tissues. You may, therefore, miss out on part of the diagnosis. However, it should be noted that endoscopic biopsy is nearly always diagnostic, but it's not 100%. The major benefit of abdominal explore is that you can run the ENTIRE gut and can take full-thickness biopsy. The major disadvantages are that you can't see the INSIDE of the gut (major disadvantage), and you actually have to open up the belly (not a huge deal, but there is more healing involved).
  7. There is NO way to diagnose IBD properly without biopsy samples. IBD is a diagnosis made using the microscope AND the rest of the physical exam and bloodwork findings. Biopsy is also the only way to try and differentiate between things like lymphocytic lymphoma (tumor in the gut) and true lymphoplasmacytic inflammatory bowel disease in cats. In other words, is this cancer or is this just inflammation.
  8. Ultrasound of the abdomen. This can be considered in lieu of the endoscopy or explore, but it isn't the kind of thing that allows you to visualize how the inside of the gut looks and it is impossible to get biopsy samples of the gut. You can often times get aspirates and those may be diagnostic. Ultrasound is typically used if we have a patient that is a poor anesthesia risk or if we happen to be ultrasounding for some other reason and can try to get information on the gut as well. Ultrasound does have a great benefit from being able to measure the thickness of the bowel.
  9. Bacterial cultures of the gut. These have varied applications. There are lots of arguments both for and against cultures and what they mean. If I find salmonella, is that bad? Just how many bacteria in the small bowel are TOO many? If I don't find campylobacter on a culture, does that mean it's not there? I believe that bacterial cultures aren't used as much as they could be because we don't always know what to do with the results.
Do I expect an owner to be willing or able to do ALL 9 of these items? Nope. Most people flat out can't even consider it. In fact, it's overkill to even try and do all 9 items at once. We may eventually get through all 9, but we always start with the first few, then treat, then think, then move forward.

Next post - treatment options.


Inflammatory Bowel Disease Part 1

Posted by Aaron

Wednesday, March 3, 2010

As I started writing this, I began to wonder why it is I seem to spend so much time talking about poop. I pondered the poop for a while and have determined that I am not, in fact, obsessed with the tailpipe. Vomiting and diarrhea are far and away one of the most common complaints we see. I can't decide if scratching/itching/ears are more common or it it's vomiting/diarrhea. So although I may seem to blog often on puke and poo, there's a reason. It's what I see all day :)

I wanted to discuss IBD because it is probably one of the most abused diagnoses I see. I'm guilty of it as well. Basically, if we can't identify specifically what's going on and it's a chronic problem, we like to label it IBD. It's easy. It's only three letters.

The total post became too long, so I've decided to break it up into three parts. Today's post is talking about what causes IBD. Tomorrow will be how to diagnose. Friday's post will be treatment options.

So what is REAL Inflammatory Bowel Disease? In its purest sense, it is EXACTLY that. But it's not that simple. (Nothing ever is, right?) Keep in mind that your gut has more surface area (by FAR) than does your skin. By default, this means that there is quite a bit of your immune system involved in policing the surface area of the gut. So let's go back to the basics. What causes inflammation?
  • Parasites. giardia, coccidia, cryptosporidium, hookworks, and whipworms start the list. These parasites each attack separate portions of the gut and their specific symptoms depend of severity. The moral of the story is that they body react to a parasite and there is inflammation generated at the site of parasitic infection. Imagine the mosquito bite or the cut/scratch you see on your skin. Imagine that same thing happening (albeit microscopically) in the gut. Same idea.
  • Dietary problems. True food allergy is a major cause of IBD and it is, IMHO, one of the more common problems. Food allergies can be insidious and kind of "creep up" on you. Owners say, "he's always eaten this food so it can't be food allergy." Nope, wrong. Food allergies almost always develop over time after chronic exposure to the same protein. Meat proteins are more likely to be the culprit. Folks like to blame grains. From what we understand now, grains are less frequently a problem than are the major meat proteins. In other words, beef, chicken, eggs, soy are more likely a problem than corn, wheat, barley, or rice. The other really important point about diet is that abrupt CHANGES in diet can also trigger inflammation. If your body is not adjusted to digesting a particular food, it can cause incomplete digestion and this can trigger issues like bacterial overgrowths or excessive stimulation of gut contractions.
  • Stress. This is more a problem in people than in pets, but I think more cats are affected by stress than we truly appreciate. Chronic stress causes chronic increases in stress hormones like cortisol. There are also increases in the body's autonomic nervous system and you get increases in epinephrine and norepinephrine (adrenalin). These nervous signals cause changes in gut motility. Parts of the gut may contract more than they should, others may not contract at all. The result is poor digestion, unpredictable absorption of nutrients, and inappropriate populations of bacterial growth.
  • Bacterial overgrowth. This is very hard to prove. You are covered from head to toe in bacteria and your intestines are no exception. The balance of bacteria in the gut plays a big role in how "happy" your gut is and how well you digest your food. There are "good bacteria" that play a positive role in your immune response, and there are "bad bacteria" that tend to generate lots of upset.
Now you see why a simple diagnosis of IBD isn't so simple? Do you also see why it is often easier to just label the problem IBD and not try to figure out EXACTLY what is causing the problem?

The even more confusing part (and you may have been thinking of this as you read through the list above) is that problems listed above are rarely mutually exclusive. Food indigestibility can be caused by the presence of a parasite and the bacterial overgrowth that occurs with the indigestion is what causes much of the symptom. It's rarely as simple as problem 1 causes symptom A and so we treat for problem 1 and it all goes away. It's the onion analogy. We have to start peeling back the layers to get to the bottom of it.

Tomorrow - Diagnosis.


I'm On The Move!

Posted by Aaron

Tuesday, February 23, 2010

There's lots of big news here in Texas. I found out last week that I have been accepted into an Internal Medicine Residency at Oklahoma State University in Stillwater, OK. I will be studying for my PhD and obtaining board certification at the same time.

By the end, I will be a boarded "specialist" in internal medicine and have the PhD. This will allow me to stay in academia and teach. My hope is to be involved in research focusing on diabetes and the hormones that fat tissue produces (called adipokines).

This is HUGE EXCITING news! We will be moving this summer and I start the new job on July 1st. I'm not sure I will be able to continue the blog. I have to see what latitude I will have while in the program. I also expect to be CRAZY busy for the next 4-6 years.

I do so love my wife! This could only happen with the support and love of my family and my wife is going above and beyond! I'm both blessed and spoiled. My daughters are excited to be going on an "adventure" and are looking forward to picking out their new house. We'll see how excited they are when it's time to actually move....

Thanks to everyone for their support and I promise to keep posting until at least July. We'll see what happens after that :)


Pearl Pee

Posted by Aaron

Dr. Herndon,
I have a question for you regarding urinary issues. I have a 4 year old pug, Pearl, with chronic urinary issues.
History-wise, our first issue was about 8 months ago when she suddenly could not urinate one morning. We rushed her to the vet, where they surgically removed a blockage caused by struvite stones. She had shown no signs of discomfort and we had no idea she had any stones up until that day. He placed us on Hill's W/D because she needed to lose a few pounds and thought it would also help regulate her urinary issues.

A few months later, we began to see blood in her urine, and dripping out after she urinated. We went back to the vet and started Primor which, we thought, cleared up the infection. We continued to feed her the W/D and I started her on an all-natural cranberry supplement.

Last weekend, the bloody urine started again. We are back at the vet today and doing another round of antibiotics. The pH of her urine today was 8. This surprised me, as I hoped that the cranberry supplement would help acidify it. Although, if my understanding of this all is correct, the infection can cause the urine to become more alkaline- regardless of what I am supplementing her with. It seems like this pattern continues, and I am not sure where to go from here.

She always has a clean water source available to her, we get her outside very often to use the bathroom, and I am just feeling exhausted with this process. I want her to feel better, and it seems like this current diet is just not helping.

I have been uncomfortable with the Hill's diet this entire time, because the ingredients just do not seem wholesome to me. I am not necessarily insistent that she be on a grain-free diet or anything, but surely there is a more nutritious food that could work similarly. I am willing to make her food at home, if that would help.

Can you offer me any advice on food/supplementing, and any other general advice for her urinary health? She is otherwise very healthy and we are so eager to rid her of these infections.

Thanks so much for any help you can offer!

-Pearl & family in Oklahoma

Isn't it amazing what they will put up with and never complain?

Everything you have said is pretty much spot on.

Urine is what is produced when the kidneys have filtered the blood and then that filtrate is concentrated, diluted, concentrated again and various electrolytes, etc are put into and taken back out of the urine. Eventually that product is dumped down-stream in the urinary bladder. All of this amazing concentration and dilution is how the kidneys regulate things like sodium, potassium, pH, and overall hydration.

ANYWAY - There are all kinds of compounds in the urine that can precipitate out in the form of crystals. This is like what happens when you make a concentrated sugar-water solution and the sugar makes those cool crystals. Crystals form when a solution is saturated enough. pH of the urine also plays a huge role. In an acid urine, the phosphate and magnesium compounds that make a struvite stone can't form. Other stones can form in any pH urine (like calcium oxalate stones), but prefer acidic urine. It's not an entirely accurate equation but acid makes oxalate, alkaline makes struvite.

Different types of bacteria can have different effects on urine pH. Some are known to produce alkaline urine and are also capable of producing the enzyme urease that causes the struvites to form.

In nearly 99% of CANINE stuvite cases, urinary tract infection is directly to blame. Treat the infection, treat the crystals. There are those fairly rare cases where the pet is able to make struvites without infection. Keyword - RARE. Oxalate stones can "just happen" and are typically much more diet related. Bichon dogs are terribly prone to oxalate stones.

There are different approaches to dietary management of these guys. Since crystals can't form if the urine is dilute, it is important to try and address that first. Increased water intake is important. This may mean canned diet. Therapeutic diets can also be used. Now this is ENTIRELY OPINION, but I don't like Hills. Never have, never will. They have some great diets (of which w/d is one of them), but Hills and I don't get along and I don't like their attitude and approach to certain disease conditions. I'm a Royal Canin man. They aren't perfect, but I sure do like them worlds better. The goal of w/d is NEUTRALITY. It's low(er) calorie, low(er) phosphate, high(er) fiber. It is a great middle-of-the-road diet for someone like Pearl. However, it does nothing to prevent crystals and nothing to dilute the urine. Royal Canin's approach is to dilute the urine first and foremost (which I think is by far the most sane approach). Hill's other diet, c/d, is designed to acidify the urine. Doesn't dilute it. It's also higher in fat. So now I have a fat dog with acidic, soupy, concentrated urine and I haven't really gained any benefit. Can you tell how I feel about c/d?

RE: naturapathic/"wholesome" food choices. I'm a fan. I think that, in general, there is something to be said about taking a more whole-food approach to diet. I like limiting the grain content (although I'm not a grain-free advocate). Cranberry is effective, but it doesn't do much to acidify. Cranberry gets its credit because the tannins in the cranberry prevent the bacteria from adhering to the bladder wall so well. If the bacteria can't adhere, they get peed out and that's not healthy for a bacteria. HOWEVER, there are no manufacturers who are trying to develop therapeutic diets that are ALSO organic, whole-food, naturapathic. When someone does, I'll probably be right there with them. If we have a specific dietary need and a disease condition to treat - we have to resign ourselves to the more traditional diet choices. These diets are fantastic, to be sure. The argument against the "traditional nutrient" approach is more philosophical than factual at this point in our understanding about canine nutrition.

So - Pearl's case is complicated by her weight and her lack of being honest with her symptoms. Her "well-loved" stature means we have to be VERY careful of her weight. Hills c/d and Royal Canin s/o are both higher in fat. W/d is a valid choice for her. Royal Canin Calorie Contral HP is also a valid choice, and would be my first choice. It will be better for weight loss and will still have similar "stuvite preventative" effects as w/d. We must STILL INCREASE HER WATER INTAKE.

We are also going to have to be pro-active with her monitoring. This means we have to continue to get repeat urine samples after the treatment is successful and monitor her for recurrence. We're going to have to go looking for the infection and not wait for it to come to us. This may mean once monthly urinalysis at a minimum.

Why does she have so many urinary tract infections? Well, there's the BIG question since we know the stones are just a secondary player. The way I answer this question (which I get frequently) is to tell you what PREVENTS a bladder infection. Any breakdown in these preventative measures will set up the possibility of infection:
  • Urethral length - it's easier for a female to develop infection than a male (in most species - cats are an exception) because the urethra is much longer in the male.
  • Normal and complete emptying of the urinary bladder. Simply put - you don't pee often enough, you set yourself up for infection.
  • Insufficient water intake. Soupy, concentrated urine ain't helpful.
  • Normal immunity along the lining of the urethra. This is a combination of antibodies the body produces (Specifically, IgA), the mucous layer of the urethra and bladder (made up of PSGAGs, glucosamine, and other large starch and protein molecules), and the anatomy of the vulva, vagina, urethra, and urinary bladder. There are all kinds of plumbing issues that can pre-dispose to urinary tract infections. If the vulva is "tucked" up high and urine pools in the vestibule or vagina, then you are pre-disposed to issues. If you're male - having testicles pre-disposes you to problems because of that annoying prostate. Intact male dogs are at higher risk than neutered male dogs (generally speaking).
Who knows which is exactly Pearl's issue. Could be a combination of all of them. Additionally, we have the question of whether the bacteria involved are being effectively killed during a course of treatment. She may have a smoldering UTI and so culture of the urine before and after treatment may be a VERY smart thing to consider. Once we culture the bug the lab will help us determine what antibiotics are most likely to work and we can make sure we're using the right one.

So my initial recommendation to you is to finish this round of antibiotics (probably 21 days worth of antibiotic) and keep rechecking the urine. I'd consider culturing the urine when she's been done with the antibiotic for at least 5 days. Your veterinarian will get the sample directly from her urinary bladder (it sounds dramatic, but it isn't). We must make absolutely certain that the infection is gone. Start her on a joint supplement. These are only going to help the bladder. Vitamin-C containing products are nice. Dasuquin and Synovi-G3 are both good products worth considering. If we are still having problems with re-infection, then ultrasound of the bladder to look for things like a polyp or pocketing of the bladder wall is a very smart move. Be patient - we can usually get to the bottom of this and then focus on prevention alone. I'm suspicious we may not be completely and totally resolving the infection or there's a polyp or some similar problem allowing the infection to keep hiding out.