A tripod joint is disclosed which has an outer joint part and an inner joint part. The ink stick body has a lateral center of gravity, and a guide element formed in the bottom surface of the ink stick body, which guide element is substantially vertically aligned with the lateral center of gravity of the body. 9% propylene glycol by weight of the composition on a formulation basis, and a method of using such composition to treat mastitis. The invention may help reduce or eliminate the need for blood drawing, sending the sample to a blood lab and having to wait for a result.