Please choose the correct ending to complete the given sentence: Pets and Animals: [header] How to stop your dog from waking you up at night [title] Consult a veterinarian about behavioral changes. [step] If your dog is waking you up more than it used to, a medical problem could be affecting its sleep or stress levels. Visiting a vet is an excellent first step so you can rule out this possibility, or catch problems early.

Ending1: [title] Pay attention to how your dog reacts. [step] Your dog might become aggressive if it becomes hyper when you wake it up. Ending2: [substeps] Dogs sleep the most at night and require rest. If your dog is repeatedly waking you up at the same time-at night, at a certain time of day, or in the morning-then your dog is more likely to wake you up. Ending3: It does also give you the opportunity to keep an eye on its behavior. [substeps] Some veterinarians recommend that dogs in their care do not wake up in the middle of the night. Ending4: Even if your pet is not sick, a vet can help you pinpoint the cause. [substeps] Any significant change in behavior or sleep schedule could be a sign of a medical problem.

Answer format: ending1/ending2/ending3/ending4