Sorry to hear about your poor girl having diarrhea for the past 3 days.
Diarrhea is one of the most common problems veterinarians treat, and can be frustrating since they can be caused by so many things. When I think about diarrhea, I like to divide it into two classes of causes:
Causes from within the gastrointestinal tract:
- parasite/bacterial overgrowth
- gastroenteritis (inflammation of the GI tract)
- upset from eating abnormal foods
- inflammatory bowel disease
- food allergies
- cancerous processes
Causes from outside the intestinal tract:
- liver disease
- kidney disease
- pancreatitis (inflammation of the pancreas leading to inappropriate release of enzymes)
- endocrine diseases like Addison's disease
Based on the fact that your girl is still acting like herself, and has a good appetite, I would probably give her another day or so of conservative at home management. Instead of mixing rice with her normal diet, I would try to mix rice with ground beef/ground turkey/chicken/cottage cheese (any one of these proteins is fine). You can give her several small meals (3-4) of this bland diet for the next day or so to see if it improves her diarrhea. If her diarrhea improves (or resolves), then I would combine this bland mixture and her normal diet, and transition her back to her regular food over the course of another 3-4 days.
If at any time during the next 36 hours, she develops lethargy, vomiting, worsened diarrhea, anorexia, blood in her stool, changes in water consumption or urination, or any other concerning changes, I would have her re-evaluated by a veterinarian right away. Additionally, if her diarrhea does not resolve by Monday, I would also have her evaluated by your veterinarian. Bringing a fresh stool sample with you to look for parasites may also be helpful. In additional to a fecal examination, and after a complete physical examination, your veterinarian will likely need to perform complete bloodwork (complete blood count, serum chemistry, and urinalysis) and may recommend abdominal x-rays and/or ultrasound.
From there, they may recommend further testing or treatment, which may include deworming medication (even if no parasites are seen), antibiotics (especially one called metronidazole, which has good activity against bacterial overgrowth in the intestines and anti-inflammatory properties within the intestines), and a prescription diet.
I hope this information is helpful and that your girl is back to normal soon. Please let me know if I can be of further assistance.