Please choose the correct ending to complete the given sentence: Pets and Animals: [header] How to diagnose heart disease in german shepherds [title] Listen for coughing. [step] Pay attention to if your german shepherd coughs for more than a few days. You may notice that the coughing is worse at night or when he's resting.

Ending1: It may even stop when he's sleeping. Don't immediately assume that something is wrong. Ending2: [substeps] You may also notice tingling in his arms as well. The dog may also have a quicker decline in muscle strength at night and an increased need to urinate in the evening. Ending3: [substeps] If your german shepherd makes a lot of whistling, tapping, or growling sounds, this may be heart disease. Try to reason with your dog so he doesn't develop heart disease. Ending4: Coughing is usually caused by fluid buildup in the lungs. [substeps] Coughing may also be a result of an enlarged heart pushing up on your dog's windpipe.

Answer format: ending1/ending2/ending3/ending4