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.
Parvovirus infections are more common in puppies and may be prevented by vaccination. Dogs with parvo will vomit and have bloody, watery stools. Fungi (especially yeast or Candida Albicans) affect the dog's intestine and stomach lining, and can also cause vomiting and diarrhea.