Please choose the correct ending to complete the given sentence: Pets and Animals: [header] How to diagnose heart failure in gerbils [title] Monitor your gerbil's weight. [step] Sudden weight gain can indicate heart failure in gerbils. Purchase a digital scale, and weigh your gerbil at least once a week.

Ending1: [title] Get veterinary attention if your gerbil has symptoms. [step] If your gerbil displays a sudden decrease in weight, then your vet may order an acc/zoster. Ending2: Some gerbils require a larger or heavier scale to monitor weight. Some gerbils may require a stockpile of pellets. Ending3: If you notice any significant weight gain, call a veterinarian as soon as possible. [substeps] To weigh your gerbil, place it on the scale and use your hands to brace the gerbil lightly without putting any pressure on the scale. Ending4: Use a warm, soapy water basin to check your gerbil's weight and for individual consideration. [substeps] As the gerbil ages, changes in weight will show up more easily on the scale.

Answer format: ending1/ending2/ending3/ending4