The reasons why dogs are obese:

1. Dogs do not control their diet and consume more energy than they consume, which can easily lead to obesity.

2. Dogs that lack exercise will easily become obese.

3. Some dogs are born prone to obesity due to genes.

4. Some diseases also cause dogs to gain weight. Such as thyroid motility deficiency, adrenal hyperactivity, etc.

The dangers of obese dogs:

1. Obese dogs are also prone to hyperglycemia, hyperlipidemia, and hypertension, which affects cardiovascular health.

2. Obesity in dogs will cause the blood to become thicker, and poor blood transportation will lead to excessive pressure on the dog's heart, thus shortening its lifespan.

3. If the dog is overweight, it will increase the load-bearing weight of the joints, leading to arthritis, and it is also easy to fracture.