Infections of the subcutis and skin of dogs caused by rapidly growing mycobacteria

Abstract

Nine dogs with panniculitis due to rapidly growing mycobacteria (RGM) were examined over 17 years. Dogs were two to 15 years; five were male, four were female. All were obese or in good condition. Antecedent injury, typically a dog bite or vehicular trauma, could be identified in some patients, while one bitch had hyperadrenocorticism. Infections involved different locations, although the cervicothoracic region, dorsum or flank were most often affected. Patients were systemically well, apart from one dog with pyrexia and two with pain or lameness. Cytology demonstrated pyogranulomatous inflammation, but in only one case was it possible to see acid-fast bacilli (AFB) in smears. Histology demonstrated chronic active pyogranulomatous panniculitis and dermatitis; AFB could be detected in only four specimens. Culture of aspirates or resected tissues demonstrated RGM in all cases, comprising six Mycobacterium smegmatis group and three Mycobacterium fortuitum group isolates. Resection of infected tissues, perioperative injectable antimicrobials and long courses of oral antimicrobials chosen according to susceptibility data generally effected a cure, although some cases recurred.

Mycobacterial Infections

“…Some dogs have a history of bite wounds or trauma. 73 Concurrent hyperadrenocorticism was described in one dog. 75 M. fortuitum can cause pulmonary disease in dogs 76-79 as well as bacteremia.…”

“…[72][73][74][75] No age, breed, or sex predisposition has been recognized, but most dogs are in good body condition or obese. Some dogs have a history of bite wounds or trauma.…”

Infectious Diseases

“…11,45,48,54,55 S. schenckii survives in the environment, typically in decaying vegetation, and people and animals Zoonotic transmission of S. schenckii between cats and people has been documented and is considered an emerging zoonosis.…”

“…In addition to FPV, the newer canine variants of canine parvovirus (CPV), specifically CPV-2a, CPV-2b, and CPV-2c reacquired the ability to replicate and cause disease in cats. 55,124,134 One of these variants contains a mutation at amino acid residue 426 of the major capsid protein, an important antigenic epitope of CPV, leading to substitution of an aspartic acid residue with glutamic acid. Parvoviruses are small nonenveloped viruses with a single-stranded DNA genome.…”

Pathological Features of Mycobacterium kansasii Infection in Black Bearded Sakis (Chiropotes satanas)

“…in histological specimens, even with acid-fast stains and especially the NTM. Some factors in tissue fixation may affect the ability of the organism to take up and retain the stain (Malik et al, 2004). In previous studies of NTM infection, acid-fast bacilli were observed in only 5 of 24 human patients, while a diagnosis was made in 20 of these 24 patients using PCR analysis on extracts from formalin-fixed and paraffin wax-embedded tissues (Hsiao et al, 2010).…”