Diarrhea, gross!! There are many different things that can cause your pet to have diarrhea, most common, table scraps and intestinal parasites. If your pet has an upset tummy, you can offer white rice and boiled chicken. Just make sure that the chicken is boneless, skinless, and contains no seasonings. Probiotics are also a good idea to keep handy for your pets. If the diarrhea worsens, please contact you veterinarian, some diagnostics testing will need to be performed.