It usually does not cause diarrhea. To start I prefer to give a half dose on the food twice a day with breakfast and supper. The body can absorb it better in smaller doses initially. You may use Arthro-IonX along with other medications or supplements. It is homeopathic in nature and so it will not negatively interact with other physical substances. In addition, I find it helpful to follow a holistic approach by giving some other nutritional supplements to accompany Arthro-IonX. Your supplements are good but I also recommend Canine Probiotics, Vitamin C, and Omega 3,6,9. Arthro-IonX will help the body to better utilize the nutrition for a synergistic response.
Please let us know how you progress or if you have any other questions.