Please choose the correct ending to complete the given sentence: Pets and Animals: [header] How to recognize signs of hip dysplasia in dogs [title] Watch your dog as he moves around and see if he' bunny hops'. [step] Dogs that have painful hips take shortened steps and tend to hold their rear legs farther forward under their bellies. This can lead to' bunny hopping', which means your dog is holding his back legs together and hopping rather than running in long strides like normal.

Ending1: Watch your dog to see if he : [substeps] Swivels his hips a lot when he walks. Holds his back legs together so that when he walks his back legs hop in a bunny-like fashion. Ending2: [title] Don't be alarmed if your dog tends to arch his back. [step] There are small breeds such as golden retrievers that are known for having hip dysplasia. Ending3: [substeps] This is called the " bunny hop " or' bunny crossing ". If your dog will not run in this way, he is most likely having trouble with hip dysplasia. Ending4: [title] Notice if your dog has a sitting posture. [step] Your dog will sit down in a squatting position to see what is up and coming.

Answer format: ending1/ending2/ending3/ending4