Use of computed tomography imaging during long-term follow-up of nine feline tuberculosis cases

Abstract

Case series summary Feline tuberculosis is an increasingly recognised potential zoonosis of cats. Treatment is challenging and prognosis can vary greatly between cases. Pulmonary infection requires extended courses of antibiotics, but methodologies for sensitively monitoring response to treatment are currently lacking. In this case series, we retrospectively examined the serial computed tomography (CT) findings in nine cats that had been diagnosed with tuberculosis. Changes in pathology (where applicable to tuberculosis) were correlated with the clinical presentation of each of the cats, the treatment protocol, and previous and contemporary diagnostic investigations. This study found that changes in CT findings during the medium- to long-term management of feline tuberculosis were highly variable between cats. The majority of cats had reduced pathology at re-examination during anti-tuberculous therapy, but pathology only resolved in a minority of cases. In some cases recurrence of pathology detected by CT imaging preceded clinical deterioration, allowing for rapid therapeutic intervention. Relevance and novel information When considered in combination with clinical findings, CT studies can aid in decision making regarding tapering of antibiotic protocols, or reintroduction of therapy in cases of recurrence or reinfection. This series also highlights that, in some cases, persistent abnormalities can be detected by CT, so complete resolution of CT pathology should not always be a goal in the management of feline tuberculosis.

Dystrophic mineralisation in chronic exogenous lipid pneumonia in cats

“…Dystrophic mineralisation of the lungs has been described in chronic pyogranulomatous pneumonia caused by mycobacteria in cats. [10][11][12] Unlike in our cases, perihilar lymphadenomegaly was the most common finding in mycobacterial infections, and radiographic changes represent usually a multisystemic disease. 11 However, non-tuberculous mycobacteria (NTM) infections may be confined to the thoracic cavity, causing consolidation and mineralisation of the lungs, 10 similar to cases 1 and 2.…”

Serial Interferon-Gamma Release Assay (IGRA) Testing to Monitor Treatment Responses in Cases of Feline Mycobacteriosis

“…Other than in a small number of cases [9,22], the use of serial IGRA for monitoring the response to antimycobacterial treatment in cats has not been investigated. The data from the current study reflect observations from human studies of treating active mycobacterial disease, in that reversion to IGRA negativity at the end of antimycobacterial therapy is uncommon [19].…”

“…Serial IGRA testing has been previously reported in a small number of cats treated for confirmed or suspected mycobacteriosis [9,22], most of whom remained positive despite apparent resolution of disease. However, it is unknown whether these findings are representative of the IFNγ response in a larger population of cats or whether we should aim for reversion to IGRA negativity when treating cases of feline mycobacterial disease.…”

Case report: systemic tuberculosis caused by Mycobacterium bovis in a cat

“…Cats are not generally considered to be an important host in the epidemiology of tuberculosis; however, mycobacterial culture results in cats showed (33%) of the feline submissions were positive for M. bovis [14]. There is no standard therapy in feline tuberculosis; however, when treatment is pursued in small animals, it should consist of a triple combination of rifampicin, macrolide and fluoroquinolone antibiotics [16].…”