[header] How to treat feline acne [title] Look for small, black spots. [step] Typically, these acne lesions are found on a cat's chin. The spots (blackheads or pimples) are small, firm and black. 
If you stroke him just under the chin, you'll notice that the skin feels gritty. [substeps] While acne is usually found on the chin, your cat may also have acne lesions above his lip.