<i>Mycobacterium porcinum</i> panniculitis in a cat from northern California

To date, in cats, <i>M porcinum</i> panniculitis has been reported from Ohio, Massachusetts and British Columbia in North America; two additional cases were reported from southeastern Australia. In humans, <i>M porcinum</i> infections have been reported from several states in the USA, predominantly in the Midwest and coastal south, but not from the west. This report extends the known spatial distribution of <i>M porcinum</i> to the western USA and strengthens its association with panniculitis in cats. It also demonstrates the need for prolonged incubation for diagnosis of some rapidly growing mycobacteria infections using culture.