The reason why the dog cannot walk on its hind legs overnight

1. Injury:

The dog may have stepped on a sharp object and been injured, causing it to be unable to walk.

2. Calcium deficiency:

Dogs eating a single type of dog food for a long time can easily cause calcium deficiency in dogs.

3. Arthritis:

Dogs may suffer from arthritis or hip dysplasia due to calcium deficiency. When arthritis attacks, dogs will experience pain and be unable to stretch their legs.