If the pill has prolonged contact with the mouth or is crushed or chewed, it may cause excessive salivation and pawing at the mouth. Side effects include nausea, loss of appetite, vomiting, diarrhea, lethargy, weakness, blood in the urine, head tilt, and stumbling. It may also cause liver disease, which can result in yellowing of the gums, skin, and eyes. Contact your veterinarian if you observe any of these effects.