The reasons why hamsters under one year old have a bowed back:

1. The phenomenon of bowed back in hamsters may be due to congenital defects. Inbreeding hamsters may have some physical defects. They are weak and sickly and are prone to contracting diseases from childhood, which are difficult to cure.

2. The hamster may arch its back to keep warm because the weather is too cold. The breeder can improve the living environment of the hamster to prevent it from catching cold.

3. The hamster may have a hunched back due to viral infection. The breeder can take the hamster to the pet hospital for testing and treatment.

4. Hamsters may suffer from rickets due to calcium deficiency or vitamin D deficiency. At this time, breeders can purchase professional drugs for treatment, or they can choose to supplement their diet by feeding fruits and pet calcium tablets.

5. The hamster may have a hunched back due to poisoning. At this time, the breeder should stop feeding immediately, take the hamster to the pet hospital for treatment in time, find the source of the hamster poisoning, and clean and disinfect the hamster cage to prevent the hamster from Secondary poisoning.