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.
Fruits and Vegetables. Most fruits and vegetables are as healthy for dogs as they are for people. Others, such as avocados, may cause vomiting and diarrhea. Onions and garlic can cause a type of anemia if fed in large or consistent doses; garlic is less potent than onions.