Small Animal Dermatology, 3rd edition

CHAPTER 34 MYCOBACTERIAL INFECTIONS 511

 Systemic nontuberculous mycobacteriosis – nontuberculosis saprophytic mycobac-

teria: cutaneous/subcutaneous infections due to rapidly growing mycobacteria: also

seen as mycobacterial panniculitis:

M. chelonae-abscessusgroup

M. fortuitum group

M. perigrinum

M. phlei

M. terraecomplex

M. genavense

M. massiliense

M. simiae

M. smegmatisgroup

M. thermoresistibile

M. xenopi.

SIGNALMENT/HISTORY

 Tuberculosis:
Source of exposure: always an infected typical host
Dogs: usually exposed from an infected person in the household (M. tubercu-

losis); route is ingestion of expectorated infectious material; aerosol exposure

possible; patients most often found in urban areas

Cats: classically exposed by drinking unpasteurized milk of infected cattle (M.

bovis); much less common now than in the past; may be exposed by predation

on infected small mammals (M. bovis, undefined tuberculosis species)

M. microti:natural infection common in voles; cats may act as a sentinel species;

can infect human beings and other mammals

Cats and dogs of any age

M. aviumcomplex: localized infections in immunocompetent hosts and dissemi-

nated disease in immunodeficient hosts; Abyssinian, Siamese, Somali cats; basset

hounds, miniature schnauzers.

 Feline leprosy syndrome:
Adult free-roaming cats and kittens
Exposure to rodents postulated; lesions develop at locations of penetrating

injury

Syndrome 1: young cats; males predisposed; localized nodular disease, affecting

limbs with sparse to moderate numbers of acid-fast bacilli present in lesions (M.

lepraemurium); cases reported from temperate coastal areas and port cities where

cats are in contact with rats; cool climate may facilitate growth of the organism

in extremities

Syndrome 2: older cats with generalized skin lesions and large numbers of acid-

fast bacilli in lesions –M. visibile(United States); additional unnamed species

reported (Australia, New Zealand);Mycobacteriumsp. strain Tarwin (Australia);

rural or semi-rural environments; risk factors of old age or immunodeficiency.