Please choose the correct ending to complete the given sentence: Pets and Animals: [header] How to diagnose hypothyroidism in golden retrievers [title] Be aware of how hypothyroidism develops in your golden retriever. [step] Hypothyroidism is caused by a low amount of thyroid hormone in your dog's body. Your dog's thyroid glands sit on your dog's neck on either side of his windpipe.

Ending1: This lets your dog breathe, but does not cause breathing issues. [substeps] A dog with hypothyroidism might have no thyroid glands at all on his neck. Ending2: Because of this, your golden retriever's thyroid glands are swollen and enlarged. [substeps] Your pooch may also develop hypothyroidism from a lack of nutrition in her diet or by not eating properly. Ending3: They produce the thyroid hormone, which helps to control your dog's metabolic rate. If your dog's thyroid glands are underactive, the thyroid will be attacked by your dog's immune system, leading to health issues. Ending4: The glands secrete thyroid hormones, such as dopamine, that are released every day to keep your dog healthy. The adrenal glands are located in the biceps and upper abdominal area and produce even more hormones than normal.

Answer format: ending1/ending2/ending3/ending4