Augmentin can have gastrointestinal effects, such as vomiting, diarrhea, or loss of appetite. Hypersensitivity to the drug can result in rashes, blood disorders, fever, or anaphylactic shock (strong allergic reaction). Prolonged use in dogs has been reported to cause ataxia, tachypnea, dyspnea, edema, and tachycardia (abnormal heart rate).