Solutions to the problem of dogs always scratching and biting:

1. Use dog-specific shower gel when bathing your dog. The dog-specific shower gel can effectively sterilize and will not cause damage to the dog's skin.

2. Under the guidance of a doctor, feed the dog an appropriate dose of anthelmintics to deworm the dog internally and externally.

3. Use a topical spray containing terbinafine, combined with a topical ointment that has a cooling effect, to effectively relieve your dog’s itching.

The reasons why dogs always scratch and bite:

1. The dog’s skin is infected with bacteria and fungi, which will cause the dog’s skin to appear. Redness, swelling, itching, etc. will lead to scratching and biting behavior.

2. Without external deworming, fleas, mites, etc. breed, causing skin itching and causing the dog to scratch and bite.

3. The owner bathes the dog too frequently or does not use dog-specific bath liquid for cleaning, which causes the normal protective layer on the dog's skin to be damaged and cause body itching.