Hugs to you and your sweet rescue doggie who is suffering from these issues along with you!
I am new here, so my ideas will not be coming from any big dog experience, but rather, generalized canine and *animal* experience. Here are just a few things to run through in your mind. If any one of them puts a light of possibility on, you can take it to your vet.
Again, I don't have a solution for this...but I'm open to share possible ideas that run through my mind.
1) Dehydration. Unfortunately, dehydration is a big catch 22 at times...becaus
e your dog is constantly voiding leaky feces, she may not be able to hold in her liquids enough to stay hydrated, based on the frequency you're describing. Her diarrhea may have initially started because of one thing, and now could *continue* for another...dehy
dration being one of the possibilities. Even if she is drinking a lot, it sounds like it's coming back out. Is she drinking normally? In OTHER animal circles...and again, I just want to clarify I am NOT professing to know whether or not this works in your dog's particular case...severe diarrhea will call for a half Pedialyte, half water solution offered as needed to remedy the emergency. Keep in mind your vet will need to tell you whether this is okay for YOUR dog or not. There could also be a problem with nutrients not even being absorbed if they are passing so quickly with the diarrhea regularly. Nutrition lacking is often a source of mood and behavior problems as well.
2) The meds themselves! Often, sulfa drugs and probiotics can wreck havoc on a body's system, and it can be hard to "catch back up" to normal stool consistency. If you haven't already (and you may have), you might even talk with the doctor about taking her OFF the meds for a week or two to see if this helps in any way by the following week. Be very aware that steroids *absolutely* affect behavior and mood over time in both animals AND people...even a short 5 day course of steroids can bring about severe and lasting mood swings until the steroids are not only stopped, but completely out of the system.
3) Anxiety/nervousness. Could it be possible that this sweet rescue doggie loves you very much and is literally making herself sick worrying about when you'll come back for her? One of our small dogs, Harvey, is a rescue. When we first got him, he was so badly neglected and abused that he did not even know how to be inside (he was forced outside and never allowed in, amongst other things). We attempted to crate train him and found that he would have horrible diarrhea IN his crate whenever we left him. A neighbor let us know that he never, ever stopped crying or barking when we left either....but when we put a diaper on him and let him roam around the house and be with Oscar, our other little dog, he stopped having diarrhea instantly and permanently!
One of the best ways to combat animal anxiety is to create a solid, well adhered to routine that stays the same...very consistent...d
aily. This would include everything from location of food dishes, time of first bathroom and wake up, time of meals, time for play, time for sitting around with the family, and time for bed. Over time, the animal can relax more because s/he knows what comes next...and can remember what the routine is comfortably, thus lessening the anxiety. Separation anxiety itself can be treated differently but this routine schedule format DOES help in many cases!
4) Allergies. What type of food does she presently eat? What are her treats? What are her supplements, if any? She could possibly have a problem with *something* in her food intake. I would recommend talking with your vet about an elimination trial to determine what, if anything, could be a culprit here. In an elimination trial diet, you take away all but the very simplest, purest, confirmed *NON* allergen ingredients and you go with those ONLY for a week, sometimes longer. If symptoms are gone, you may have a food allergy! If they are not gone, a food allergy could be a problem, but may not be the primary source of concern.
5) You say every 3rd to 4th day...is there a change in her routine, YOUR routine, or ANYONE'S routine in your home? Does someone work a different shift some days of the week? Is there a change in the time that the dog gets fed? Etc., etc.
6) Loose stool overall...some dogs just have it. Usually it is related to dietary or nutritional needs but anything is possible.
I sure hope you get to the root of it!
Above all else, I can just feel how tired your body and heart are from this tough regimen of dealing with the constant mess, concern, and failed treatments for the diarrhea. Take a deep breathe and wrap your arms around yourself and remember how wonderful you are for rescuing this dog in the first place. You can do it! I am sending you lots of positive energy for peace, renewal, and a fresh perspective to help get to the root of the issue. If there is anything else I can do, please let me know!
Love and Hugs,
Jen and Balthie