Here is a list of warning signs, provided by the American Veterinary Medical Association, to let you know when you should consult your veterinarian:

• Abnormal discharges from the nose, eyes, or other body openings
• Loss of appetite, marked weight losses or gains, or excessive water consumption
• Difficult, abnormal, or uncontrolled waste elimination
• Abnormal behavior, sudden viciousness, or lethargy
• Abnormal lumps, limping, or difficulty getting up or lying down
• Excessive head shaking, scratching, and licking or biting any part of the body
• Dandruff, loss of hair, wounds, open sores, and a ragged or dull coat. Foul breath or excessive tarter deposits on teeth