Canine Leishmaniasis update on diagnosis and therapy. Part I: Diagnostic approach

The first edition of the guidelines for the diagnosis of canine leishmaniasis (CanL) has been prepared by the "Canine Leishmaniasis Working Group" (CLWG) in 2007. Since then a great number of papers on CanL has been published. Some of them describe innovative methodology aspects, other papers provide further details on specific disease features, such as histopathology and molecular biology. Overall, the studies carried-out on CanL in the period 2007-2010 confirm the diagnostic approach elaborated and published by the CLWG in 2007. Although new Leishmania antigens have been obtained and new set-up, the choice of the diagnostic method remains linked to (i) clinical signs shown by the dog, (ii) aim of the test (i.e. screening or diagnosis), and (iii) local epidemiological conditions, rather than to a diagnostic yield difference of the tests used, as previously suggested in the CLWG guideline. From the literature, the unique important novel finding appears to be represented by the possibility to use samples such as urine and conjunctival swabs that can be easily obtained. Specifically, conjunctival swabs to traditional samples. Observing Leishmania amastigotes in those samples is useful to diagnose the infection, to define the prognosis (e.g. association between urine Leishmania amastigotes and severity of renal lesions) or to monitor progression of the infection in exposed dogs (e.g. conjunctival swabs becoming positive).