Intracardiac tuberculomas caused by Mycobacterium tuberculosis in a dog

Abstract

BackgroundThis paper presents an unusual form of disseminated Mycobacterium tuberculosis infection in a dog. The infection lasted at least one year and its main gross lesions were massive cardiac tuberculomas. To the best of our knowledge, this is the first report of heart tuberculomas in a dog.Case presentationA 9-year-old mixed-breed male dog weighing 10 kg was referred to the clinic for cardiological evaluation before general anesthesia. The echocardiography revealed a lump of about 20 mm in diameter in the area of the left atrium. Almost one year later the same dog was presented again in severe clinical state (fever, anorexia, weight loss, depression, cough, dyspnea, lymphadenomegaly, vomiting, recent episodes of fainting). Due to progression of the disease and poor effects of treatment the owner decided to euthanize the dog. Most prominent lesions observed during autopsy were diffuse pneumonia, fibrinous pericarditis and epicarditis as well as large, yellow, semisolid masses of caseous necrosis in the left and right atrium (30 mm and 15 mm in diameter, respectively). From both pulmonary and cardiac lesions M. tuberculosis was isolated on Lowenstein-Jensen slants and in Bactec Mycobacteria Growth Indicator Tube 960 liquid media, and confirmed by BD ProbeTec ET Direct Detection Assay and spoligotyping.ConclusionCompanion animals may occasionally suffer from tuberculosis but majority of cases probably remain misdiagnosed or undetected. Typically tuberculosis in dogs affects lungs and their regional lymph nodes. Even in humans tuberculomas are rare manifestation of mycobacterial infection, mostly seen in the central nervous system. Atypical location of main tuberculous lesions may account for lack of correct ante mortem diagnosis in this case.

Emerging source of infection – Mycobacterium tuberculosis in rescue dogs: a case report

“…The import of rescue animals at the present extent is a relatively new phenomenon and is increasing heavily. Given the number of reports of single tuberculotic canine cases with striking similarities in the background data [6][7][8][9][10][11], it is reasonable to think that there are numerous unidentified cases among imported dogs in a repeating pattern that have gone unnoticed. In addition to the owners, vulnerable individuals and other pets that may be predisposed to lengthy exposure periods, the work safety of the personnel at veterinary clinics, and even more so the pathologists and personnel at autopsy are of highest importance, because they have an elevated risk of infection while working in close contact with diseased animals.…”

“…Therefore, M. tuberculosis infection in dogs may be termed an 'anthropozoonosis' [5]. There are a limited number of reports of sporadic M. tuberculosis cases in dogs, and in all of them the most likely source of infection was a human companion [6][7][8][9][10][11]. In these cases the infected organs varied between lungs, lymph nodes, intestine, liver, kidneys, spleen and heart, and the disease was most often disseminated.…”

Mycobacterium tuberculosis SIT42 Infection in an Abused Dog in Southern Italy

“…In naturally infected dogs, TB commonly shows a subclinical course for long periods (9,14), but, when clinical signs are developed, they are described to affect primarily lungs and regional lymph nodes; nevertheless, different localizations have been described (15,16). The ante mortem diagnostic approach of canine TB is difficult for the absence of symptoms in infected dogs (9,14), complicated by the absence of a validated immunological assay (3,12).…”

An outbreak of tuberculosis due toMycobacterium bovisinfection in a pack of English Foxhounds (2016-2017)

“…In the UK, however, the significance of M. bovis in companion animals is largely limited to domestic cats, were frequent diagnoses are made (Broughan et al., ; Gunn‐Moore, ; Pesciaroli et al., ; Rocha et al, ). Canine incidence of TB in the UK is currently considered to be rare, and almost all reported cases are limited to individual sporadic infection or small numbers of epidemiologically unrelated cases (Ellis et al., ; Gay et al., ; Liu, Weitzman, & Johnson, ; Park, Lim, Kwon, Bae, & Park, ; Parsons et al., ; Pesciaroli et al., ; Posthaus et al., ; Shrikrishna, de la Rua‐Domenech, Smith, Colloff, & Coutts, ; Snider, ; Szaluś‐Jordanow et al., ; Van Der Burgt, Crawshaw, Foster, Denny, & Schock, ).…”