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.
Food allergies are extremely severe and may cause inflammation of skin, nausea, vomiting, unconsciousness and even death. Dogs that have a food allergy may not even have any observable symptoms until their condition begins to take a turn for the worse.nhalant Allergy. The symptoms of allergy are different for each different cause. The most common symptoms of allergies in dogs are itching and formation of lesions on the skin. Usually when a dog is experiencing an allergy, it scratches itself a lot and may also break the skin, creating an open wound.