The hair follicles on some cats' chins can produce excessive sebaceous material and keratin, says Vet Nikki Gaut...
Vet Nikki Gaut advises...
The hair follicles on some cats' chins can produce excessive sebaceous material and keratin (the protein in skin and hair) and these hair follicles become plugged with black sebaceous material forming comedones (or blackheads). This is often noticed more on paler-coloured fur, with the flecks of black being mistaken for flea dirt.
A resulting secondary bacterial infection may lead to folliculitis?(inflammation of the hair follicles) and formation of pustules from which pus may be expressed. If this worsens, many hair follicles are affected and the whole chin may become infected with swelling, inflammation, discomfort and further discharging of pus.
Clipping the hair in minor cases and using an antibacterial wash two to three times daily, can help prevent this. It has been reported that using ceramic or metal bowls rather than plastic, as well as cleaning the chin after eating may reduce the incidence. If infection is present your vet may prescribe a prolonged course of antibiotics or anti-fungals.