Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2023 Jul;35(4):438-442.
doi: 10.1177/10406387231176816. Epub 2023 May 19.

Canine leproid granuloma caused by a member of the Mycobacterium tuberculosis complex

Federico Giannitti  1 , Matías A Dorsch  1 , Sofía Fernández-Ciganda  1 , Ana Rabaza  1 , Sebastián Vázquez  2 , Deborah César  3 , Joaquín Hurtado  4 , Gonzalo Greif  4 , Demi B Rabeneck  5 , Julu Bhatnagar  5 , Jana M Ritter  5
Affiliations

Canine leproid granuloma caused by a member of the Mycobacterium tuberculosis complex

Federico Giannitti et al. J Vet Diagn Invest. 2023 Jul.

Abstract

Canine leproid granuloma (CLG) is a chronic form of dermatitis that has been associated with nontuberculous mycobacterial infections in Africa, Oceania, the Americas, and Europe. We report here a case of CLG associated with a member of the Mycobacterium tuberculosis complex (MTBC), which could be of public health concern. An 8-y-old pet dog developed 0.5-1-cm diameter, raised, firm, nonpruritic, alopecic, painless skin nodules on the external aspects of both pinnae. Histologic examination revealed severe pyogranulomatous dermatitis with intracellular Ziehl-Neelsen-positive bacilli that were immunoreactive by immunohistochemistry using a polyclonal primary antibody that recognizes tuberculous and nontuberculous Mycobacterium species. DNA extracted from formalin-fixed, paraffin-embedded skin sections was tested by a Mycobacterium genus-specific nested PCR assay targeting the 16S rRNA gene. BLAST sequence analysis of 214-bp and 178-bp amplicons showed 99.5% identity with members of the MTBC; however, the agent could not be identified at the species level. Although CLG has been associated traditionally with nontuberculous mycobacterial infections, the role of Mycobacterium spp. within the MTBC as a cause of this condition, and the role of dogs with CLG as possible sources of MTBC to other animals and humans, should not be disregarded given its zoonotic potential.

Keywords: Mycobacterium tuberculosis complex; canine leproid granuloma; dermatitis; dogs; pathology; pyogranuloma.

PubMed Disclaimer

Conflict of interest statement

The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Figures

Figure 1.
Figure 1.
Gross appearance of the cutaneous mycobacterial pyogranulomas in an 8-y-old dog. Multifocal-to-coalescing 0.5–1-cm diameter raised alopecic nodules in the skin of the right pinna.
Figure 2.
Figure 2.
Microscopic images of the cutaneous mycobacterial pyogranulomas. A. Pyogranulomatous dermatitis. H&E. B. A multinucleate giant cell contains numerous intracytoplasmic, acid-fast bacilli. ZN stain. C. Scattered Mycobacterium spp. antigen immunoreactivity. IHC with rabbit polyclonal antibody against Mycobacterium spp. purified protein derivative. Hematoxylin counterstain.
See this image and copyright information in PMC

References

    1. Bhatnagar J, et al.. Improved detection and accuracy of Mycobacterium species identification from paraffin embedded tissues of patients by using multigene targeted PCR and sequencing. Open Forum Infect Dis 2017;4(Suppl 1):S620–S621.
    1. Charles J, et al.. Cytology and histopathology of canine leproid granuloma syndrome. Aust Vet J 1999;77:799–803. - PubMed
    1. Dedola C, et al.. First report of canine leprosy in Europe: molecular and clinical traits. Vet Rec 2014;174:120. - PubMed
    1. Foley JE, et al.. Clinical, microscopic, and molecular aspects of canine leproid granuloma in the United States. Vet Pathol 2002;39:234–239. - PubMed
    1. Frothingham R, Meeker-O’Connell WA.Genetic diversity in the Mycobacterium tuberculosis complex based on variable numbers of tandem DNA repeats. Microbiology (Reading) 1998;144:1189–1196. - PubMed

Substances