Less serious side effects include: 1  Loss of appetite. 2  Weight loss. 3  Nausea. 4  Vomiting. 5  Diarrhea. 6  Frequent urination. 7  Muscle cramps, painful and swollen joints. 8  Excessive tiredness. 9  Difficulty falling asleep. 10  Headache, nervousness, dizziness. 11  Depression, mood swings. 12  Vivid dreams.
Nausea can occur in dogs for many reasons, particularly when the digestive tract and nervous systems are out of balance. Stress can certainly play a role in nausea.
Dogs can vomit because they have worms. You can give your dog over-the-counter Panacur C, which is effective against stomach worms, esophageal worms, roundworms, hookworms, tapeworms, and whipworms. Although cats can safely use Panacur C, it is not approved for use in cats by the FDA. For cats with worms, Drontal (Rx) can be prescribed.