Q: My 11-year-old female Labrador Retriever was just diagnosed with an enlarged heart. The vet told me it was from old age. I was wondering how much I can exercise and play with her without harming her?

A: Finding the proper activity level depends on the severity of your dog's heart disease and the signs she has demonstrated. These dogs should be encouraged but not forced to exercise. A reasonable exercise program will help to maintain overall health and preserve remaining cardiopulmonary function. Nutritional and medical treatment of many heart conditions can result in improved exercise tolerance and ability. Weight control is helpful in cardiac patients, and physical activity certainly enhances any weight loss program. Your veterinarian knows your dog's condition best and should be consulted for details.

Avoid overexertion, overly prolonged exercise and exercise in hot and/or humid conditions. Watch your dog closely for signs of distress. Weakness, increased coughing or respiratory effort, reluctance to continue exercising and failure to recover normally after exercise indicate the activity might be too strenuous. Don't depend on your dog to limit her own activityher willingness to please you might outweigh her remaining cardiopulmonary health. Use common sense and your dog should be OK.