My client roster escalates with cases of gastrointestinal (GI) troubles every spring. A typical email from a client at this time of year will explain that the dog seems to have episodes of soft stool (if not worse) every spring, or fall. The client tries everything they can think of to improve matters, finally ends up at the vet who often prescribes an antibiotic. Sometimes it works, and sometimes it doesn't, or it works as long as the dog is on the antibiotic, but there's a relapse 1-2 weeks later. So, what the heck is going on?
Since dogs don't have zippers down their bellies, I can't know with certainty, but I think the following makes some sense. Bacteria that may not have been readily available to the dog during another time of year becomes available as the weather gets warmer. Dogs stick their faces in all kinds of things, often licking the grass, or dirt, sometimes eating it as well. Those that don't do it are walking on it anyway, and then lick their paws, nails, etc.. In all cases, dogs that have a miraculous turnaround when an antibiotic is given (assuming it's the right antibiotic) are making it pretty clear that they have/had a bacterial issue of some kind. After all, that's what an antibiotic addresses.
What I find most interesting (and frustrating at times) is when there's an overgrowth of clostridium perfringens bacteria. How's that for a name? Rolls right of the tongue, doesn't it? C. Perfringens is found in soil, sewage, raw meats, and grows when a cooked food is left to sit and reaches a temperature of 68-140 F ( 20-60 C). So, imagine the dog that's eating a bit of dirt in the spring/summer, finds a tidbit of meat on the ground, or raids a garbage can...you see where this is going. Not all dogs become ill, but many do. It's not the bacteria that's the main problem. The toxins it produces are what make a dog (or person) sick. IDEXX labs offer a diarrhea panel that's considered diagnostic, but a blood test that checks vitamin B-12 and folate is the usual way of checking. Low B-12 and elevated folate are highly suggestive of the bacterial overgrowth, so an antibiotic is given. The trick is to give it for a long enough period of time, and sadly, not everyone will agree to do it. I say sadly because it's the only way to kick the bacteria into submission.
Inflammation in the gut can easily translate to a sensitivity to dietary fat, and even feed the problem. Your dog may be able to return to his/her regular diet, but a highly digestible, lower fat food is a good bet right now. In many cases, a bit of dried, or fresh mint will help as well. Mint works as an antispasmodic, and can lessen the urgency to "go". I've often added a mint tea (use the herb, not the bagged teas) to home-made diets in these cases. One teaspoon per 10 pounds of body weight seems to help most dogs.
A healthy dog might have a day of mysteriously sloppy stool that corrects without intervention. However, a dog that's compromised is a different story, and the truth is that you may not have known about the compromise in the gut to begin with. Why would anyone suspect a problem when the dog has been well? It's only when there's an obvious issue that we tend to start thinking harder about these things...which brings me to my point about being proactive. Here's how:
The gut environment changes every time the diet is changed. Try to keep a fairly consistent diet. That doesn't mean you must feed every bit of a balance diet in one day, or never change a food, but the bigger the change (especially in fat and fiber content), and the faster you make it, the more challenging it is for the gut.
Despite persuasive claims and advertising, the fact is that nobody knows all the bacteria in the canine gut, and it changes based on the diet anyway. The one sure-fire probiotic is L. acidophilus, so why not add a little more of the good stuff? Be sure the diet is balanced. Something as basic as being low in one B vitamin can cause digestive problems.