Table 6.

Laboratory methods for diagnosis of Leishmania infection in cats

Method	Principle	Features	Recommendations	References
Serology	Detection of specific antibodies by IFAT and ELISA (more frequently used), DAT and WB	Different sensitivities and specificities, partially dependent on the cut-off values; clinical cases may have from low to high positive antibody levels, but the latter are usually diagnostic	Antibodies should be evaluated using techniques validated in cats; parasitological methods should be employed in clinically suspect but seronegative or low positive cats	[23–25, 82–84]
Cytology	Detection of amastigotes in stained tissue smears (ex: lymph node, bone marrow, skin and cornea)	Specific, but time-consuming and requiring expertise	For compatible skin or mucosal lesions, enlarged lymph nodes and other lesions, and for clinically suspected cases if serology is negative or low positive	[50, 61, 63, 65]
Histology with IHC	Detection of amastigotes in histopathology tissue specimens	Specific, but time-consuming and requiring expertise		[59, 68, 69, 72]
		IHC is not widely available
Culture	Multiplication of promastigotes from tissues	Not suitable for rapid diagnosis and not widely available	For research and species and/or strain identification	[26, 37]
PCR	Amplification of parasite DNA from tissues and biological fluids, including blood, buffy coat, bone marrow, lymph nodes and conjunctival swabs	More sensitive than cytology or histology with IHC; may allow molecular characterization and quantification of the parasitic load	Preferable to sample more than one tissue, in order to increase sensitivity of detection especially in subclinical infections	[24, 66, 69, 97, 98]

DAT: direct agglutination test; ELISA: enzyme-linked immunosorbent assay; IFAT: immunofluorescence antibody test; IHC: immunohistochemistry; PCR: polymerase chain reaction; WB, western blot