Since she's been out on the street..who knows what she's eating, and what she's encountered. Thank you for trying to help her!
The diarrhea could be a reaction to some garbage she got her paws on...or the switch to better food from you. I'm definetely thinking worms could be a culprit! Normally, with heavier infestations, you can actually see them in the stool!
if you see long stringy things or what looks like grains of rice..that's probably it. Depends on how long she's been out, and the quality of her life so far.
I would really want to take her to the vet..they can scan her to see if she's microchipped and maybe her owner is out there looking for her! At the very least you can get her all checked out so that you can maybe foster her for a while until you figure out if a shelter/rescue group can take her in. Being that she's part boxer, I bet you'd have no problem finding her a home! Maybe your vet can cut you a deal on the bill since you are trying to help..or you can contact your local SPCA to see if they can or know a clinic that would check her out at minimal cost. many rescue groups will foot the bill if you help them with fostering her.
But you'd need to get her checked for parasites, fleas, etc. before allowing her contact with your dog. Where is she eliminating? Is she having the diarrhea in your yard? You want to make sure you are cleaning up after her if she is eliminating anywhere near your dog hangs out..to not risk infecting your dog as well.
The fact that she drinks a lot of water can be a cause of concern too. She may be really dehydrated in which case a couple of hours of IV fluids may be beneficial.
When I would get parasite ridden, skinny fosters...I would give them puppy food to get more calories and nutrients in. I would supplement it with bland things..like ground beef, white rice (to help bind the poop), pumpkin purree (not pumpkin pie mix), yogurt, etc.
These things will help greatly if all she's got is a bad tummy...but if there are parasites in her you'd want to get her dewormed so that she isn't in further danger. You'd also want to test for heartworm too...that parasite is very difficult to cure.
The laying around could be all tied to her being ill...and it could also be her being shy and unsure of her surroundings. I've had fosters that took a week to let me pet them..and once they saw that I gave them good food, and attention and that I wasn't going to hurt them..their true colors and personality came shining through and they were like a totally different dog!
Good luck and please keep us posted!!
