Article in English: Adult rabbits can also show hostile mating behavior, but they are often less inquisitive of their environment. Adult rabbits tend to be active when awake and feeding, and divide their time between these activities and sleeping. When they are awake they give the impression of being alert and interactive. Older rabbits tend to sleep more and eat less, and may be prone to losing weight and become skinny. When they are awake they may react less to things going on around them, and seem less interested in their environment. A young rabbit is still growing, so you should be able to spot a change in size. An adult rabbit is at the peek of their physical powers and is likely to have a glossy, shiny coat, have bright eyes, be a good weight (possibly even plump) and move in an easy fluent manner. In contrast an older rabbit may have a dull coat, because they don't groom themselves as much. They may have impaired vision or hearing, and not interact with their environment as much as an adult rabbit. When they move they are liable to look stiff, and move awkwardly, perhaps shuffling along rather than hopping. There is no scientific link between sore hocks and age, but some rabbit keepers have noticed that older animals are more likely to have sore hocks. This condition is caused by the animal's body weight pressing down on the thin skin of their hocks, causing the fur to rub away and thick skin to develop.  There are many variable factors in the development of sore hocks, which include the animal's weight (the heavier the rabbit, the more likely sores are to form), the depth of their bedding (lack of bedding is a risk factor), and how clean or dirty the bedding is (Urine soaked bedding scalds the fur and causes it to fall out). It is unlikely a young rabbit has all of these factors in place, so sore hocks are rare in a young rabbit. However, the older the rabbit gets the more it is likely these factors occur, resulting in hock calluses. Rabbits can suffer from overgrown teeth at any age, as this can be caused by their diet...

Summary in Vietnamese:
Quan sát một số hành vi để biết thỏ là thỏ trưởng thành hay thỏ già. Đánh giá ngoại hình chung của thỏ. Quan sát dấu hiệu viêm da chân. Quan sát răng thỏ.