There may be a variety of reasons why dogs often sit crookedly, some of which may be related to their physical health. Here are some reasons that may cause dogs to sit crookedly: 1. Joint disease or bone deformity: Dogs may feel discomfort due to joint disease or bone deformity, so they will choose a more comfortable sitting position. For example, arthritis or other joint problems may cause a dog to be unwilling to bear its weight and choose to sit crookedly. 2. Muscle Problems: Muscle problems in dogs may also cause them to adopt unusual sitting positions. This may include issues such as muscle atrophy or muscle tightness.

3. Nervous system problems: Nervous system problems in dogs may also affect them sitting position. These problems may include nerve damage or neurological disease.

4. Other health problems: In addition to the above reasons, dogs sitting crookedly may also be related to other health problems, such as digestive system problems, respiratory system problems, etc.