Mrs. Smith was leaning against the wall in the exam room, eyes half closed with dark circles underneath. On the floor in front of her was Rambler, her normally rambunctious German Shepherd. The look on both of their faces suggested that it had been a long night last night. The note at the top of her file said “bloody diarrhea”. I have seen this scene so many times I could probably describe the events of the past evening without even hearing her story.

“He had me up every fifteen minutes all night long, rushing out to go to the bathroom, but when he got out there he just strained and strained. Then sometime around 4:00am he didn’t make it all the way outside and left this huge bloody mess on my living room carpet. Now today he doesn’t want to eat and I am really worried about him.”

Further history uncovered that Rambler got to eat the unwanted pizza crusts from dinner two nights ago, and with the stool sample that Mrs. Smith kindly brought in with her (so Rambler did not have to suffer the indignity of us having to extract one at the office) we were able to quickly diagnose his condition as colitis, inflammation of the colon, due to bacterial imbalance. Some simple antibiotics were prescribed and Rambler and the Smiths were well on their way to a more comfortable night this evening.

I see this type of case at least daily in practice, but in spite of the fact that this is a common problem, many people don’t know about it. The usual trigger for this situation is when a dog gets food that is different from what it normally eats. Common offenders are table scraps, a different brand of dog food, or a garbage eating spree. I also see this in dogs that have been stressed from staying at a kennel or having other major changes in their routine. The different food or the stress can shock the gastrointestinal tract, which causes some of the wimpier bacteria that live there to swoon and die off. There are some bad acting bacteria that normally lurk in the colon in small numbers that will quickly take advantage of all the newly open real estate. The lurkers, when growing in larger than normal populations, can start producing toxins that irritate the lining of the colon.

At first the colon tries to protect itself by secreting extra mucous. Owners may notice a gelatinous material on the outside of the stool. Many dogs will correct themselves at this point and the problem may resolve without any outside interference. Sometimes the bacterial toxins tip the balance too far and the dog will begin to have progressively looser stools until, at the far end of the spectrum, they can be very watery and bloody. The other hallmark of this problem is the sudden, uncontrollable, dash-to-the-door-and-frantically-tap-dance urges that always seem to happen when everyone would rather be sleeping. Dogs will often appear constipated because they strain and don’t produce much, but this is usually a result of an empty but very irritated colon. In some cases dogs will also vomit and run a fever.

It is important to note that there are several things that cause similar symptoms and a proper diagnosis and appropriate treatment cannot be achieved without a complete exam and some testing. Fortunately, bacterial imbalance from dietary indiscretion is common and often responds quickly to fairly simple treatment.

So why do I bring up such a delightful topic so close to Thanksgiving? Although it is not always possible to anticipate the clever ways our dogs will find to help themselves to all the abundant goodies around during the feast, at least we have control over what we intentionally give to them. Sharing your Thanksgiving meal may very well have no negative impact on your dog whatsoever, but it is a little like playing Russian roulette with the potential for a future evening of bloody diarrhea. I often find it is harder to train people not to give table scraps than it is to train the dog, so my rule is that whoever is responsible for giving the offending item is also responsible for chaperoning the midnight dashes outside and for operating the carpet cleaner when needed. One bout is usually all it takes for the serial treat-sneaker to find that an ounce of prevention is worth a pound of carpet cleaning solution.