A cat's swollen chin and pustules may be caused by a variety of reasons, but it may also be caused by parasitic invasion such as mites, bacterial infection, trauma, allergic reactions, etc.

When an abscess is found on the cat's chin, timely treatment is required, which includes cleaning and disinfecting the affected area, using anti-inflammatory ointment or spray, Oral or injected antibiotics may also be used for treatment when necessary.

Poop scrapers need to regularly deworm the cat internally and externally, maintain the cat’s oral hygiene, and other preventive measures can also help reduce the risk of cats developing chin pustules. When dealing with this type of problem, it's best to seek the advice of your veterinarian to ensure the correct treatment is taken.