Please choose the correct ending to complete the given sentence: Pets and Animals: [header] How to fit a dog backpack [title] Consult your veterinarian. [step] While most dogs can use a backpack with no problems, some dogs with pre-existing health issues or skeletal problems should avoid using one. Talk with your veterinarian to see whether your dog is a candidate for wearing a backpack.

Ending1: [substeps] If your dog has significant issues with its back, such as arthritis, wear a backpack made of supportive cushioning like padding or plastic. If your dog is concerned that your dog is too bulky, then beware of adopting a backpack which creates a more visible strain on his joints. Ending2: Your veterinarian will be able to give you tailored advice on how to make a flexible backpack. [title] Consider your dog's age and weight in relation to the backpack. Ending3: [substeps] Dogs that are not yet fully grown should not wear backpacks, because they can develop stressed joints or arthritis. [title] Measure your dog's girth. Ending4: Ask what kind of backpack they recommend, and ask how the backpack should be made to protect you from the elements. [substeps] Some backpacks will include a wrist strap.

Answer format: ending1/ending2/ending3/ending4