Please choose the correct ending to complete the given sentence: Pets and Animals: [header] How to diagnose dental disease in dogs [title] Pay attention to unusually bad breath. [step] If your dog's breath is worse than usual, it could be a sign that your dog has dental disease. With dental disease, bacteria and infected tissue can exude a putrid smell once it has developed quite a bit.

Ending1: This can cause poor hygiene and, during chronic dental problems, in many cases, even death. [title] Be on the lookout for: licks, biting. Ending2: [substeps] Dogs can have bad breath for a wide variety of reasons. The key is to identify when the smell changes or becomes markedly worse. Ending3: [substeps] The alteration in the odor is the most noticeable difference between the usual normal smell and a more pungent odor. The one major difference is that dental disease does not leave behind a scent; just it dissolves it. Ending4: For example, a dog with gingivitis may develop bad breath. [substeps] Infected gingivitis doesn't smell good on your dog.

Answer format: ending1/ending2/ending3/ending4