We evaluated the titers of anti-T. gondii antibodies by various serological
tests in 40 serum samples from dogs exhibiting clinical signs of infectious
diseases. Indirect immunofluorescence (IgG-IFI), indirect haemagglutination
(IHA and M-Toxo) and immunoenzymatic (ELISA and PA-ELISA) tests were
carried out. Titers =/} 64 were considered as positive. Anti-Toxoplasma
antibodies were found in 9 (22.5%), 14 (35%), 14 (35%) and 12 (30%)
samples, respectively for IHA, IgG-IFI, ELISA and PA-ELISA. The results
showed that 57% were negative in all tests and 43% of the dogs presented
antibodies to T. gondii; from these, 20% were positive in all three tests
with high titers of antibodies and 23% were positive in only one or two
tests with low titers of antibodies and mainly related to the IFI and ELISA
tests. We observed 5 (12.5%) and 1 (2.5%) reactive samples, respectively,
by M-Toxo and IHA with or without 2-mercapthoethanol, in the attempt to
detect specific IgM. We can conclude that serodiagnosis of toxoplasmosis in
dog have to be based on the combination of serological tests (IFI and
ELISA) and with emphasis at the determination of the titers and the classes
of the specific antibodies.
