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.
Like people, your dog stomach problems can be due to motion sickness. 1  Symptoms: Symptoms of dog motion sickness include excess salivation, yawning and vomiting. 2  Treatment: Treatment is also similar to humans with the use of Dramamine (dimenhydrinate) and Gravol.