Protozoal infections of the cornea and conjunctiva in dogs associated with chronic ocular surface disease and topical immunosuppression

Abstract

Protozoal keratitis and conjunctivitis without systemic involvement appears rare and may be associated with chronic preexisting ocular surface disease treated with long-term immunosuppression. Based upon clinical appearance, lesions could be confused with neoplasia. This is the first report of amoebic keratoconjunctivitis in dogs and of L. mexicana in dogs in the United States.

Infectious crystalline keratopathy in dogs and cats: clinical, in vivo confocal microscopic, histopathologic, and microbiologic features of eight cases

“…The role of cyclosporine in the development of ICK requires further investigation; however, it is plausible that this medication contributed to the local immunosuppressed state that permitted development of ICK in the dogs of this report. Atypical corneal infections are previously described in dogs during cyclosporine therapy . Some of the dogs described in this series were also affected by immunosuppressive systemic diseases or receiving immunosuppressive systemic therapeutics.…”

Toxoplasmosis as a cause of life‐threatening respiratory distress in a dog receiving immunosuppressive therapy

“…A reduction of IFN‐γ may also reduce the anti‐parasitic ability of macrophages, natural killer cells and nonimmune cells, hence allowing intracellular growth, transmission and proliferation of T gondii . Systemic toxoplasmosis has been described after monotherapy with ciclosporin in cats and localized toxoplasmosis may also occur in cats and dogs . However, it must be noted that fatal toxoplasmosis in cyclosporine‐treated cats is uncommon and a direct inhibitory effect of ciclosporin metabolites on T gondii proliferation has also been described .…”

Bilateral Sterile Pyogranulomatous Keratitis in a Dog

“…Previous reported cases of pyogranulomatous keratitis in the dog identified several protozoal organisms (ex. Toxoplasma gondii and Leishmania ) as well as Acanthamoeba as causative agents with visualization of organisms followed by confirmatory ancillary testing [6–8]. The Beckwith-Cohen et al protozoal keratitis cases were all identified in dogs that had received long term, topical or systemic, immunosuppressive therapy for keratoconjunctivitis sicca before masses were noted to be progressing over the corneas.…”