Changes

Firstly, clinical signs should be suggestive of toxoplasmosis, despite variation in the presentation of disease between individuals. Although no pathognomic changes for toxoplasmosis are seen on routine haematology, biochemistry and urinalysis, certain results results are often seen in ''T. gondii'' infection. For example, most cats show a mild non-regenerative anaemia, and 50% of pateients are initially leukopenic due to lymphopenia. Neutropenia may occur in conjunction with lymphopenia, and leukocytosis may occur during recovery⁴. Most patients also show and increase in creatine kinase, ALT, SAP, and hypoalbuminaemia is also common^{1, 4}. 25% of cats show hyperbilirubinemia and icterus, and pancreatitis may cause low to low normal serum calcium. A mild proteinuria and bilirubinuria are often revealed by urinalysis.

Firstly, clinical signs should be suggestive of toxoplasmosis, despite variation in the presentation of disease between individuals. Although no pathognomic changes for toxoplasmosis are seen on routine haematology, biochemistry and urinalysis, certain results results are often seen in ''T. gondii'' infection. For example, most cats show a mild non-regenerative anaemia, and 50% of pateients are initially leukopenic due to lymphopenia. Neutropenia may occur in conjunction with lymphopenia, and leukocytosis may occur during recovery⁴. Most patients also show and increase in creatine kinase, ALT, SAP, and hypoalbuminaemia is also common^{1, 4}. 25% of cats show hyperbilirubinemia and icterus, and pancreatitis may cause low to low normal serum calcium. A mild proteinuria and bilirubinuria are often revealed by urinalysis.

Demonstration of antibodies in serum, aqueous humour or CSF is indicative of exposure to ''T. gondii'', but does not necessarily show active infection. This could be overcome by testing for ''T. gondii'' antigen or immune complexes, but these methods are currently only available to researchers. Several techniques are commercially available for detection of antibody, including ELISA,

Demonstration of antibodies in serum is indicative of exposure to ''T. gondii'', but does not necessarily show active infection. This could be overcome by testing for ''T. gondii'' antigen or immune complexes, but these methods are currently only available to researchers. Several techniques are commercially available for detection of antibody, including ELISA,

immunofluorescent antibody testing, western blot immunoassay, Sabin-Feldmann dye test, and agglutination tests. Although these tests are theoretically able to detect all classes of immunoglobulin against ''Toxoplasma gondii'' in many species, it seems that feline serum positive for IgM only often reads as a false negative^{5, 6} and so careful interpretation is necessary, particularly since the IgM antibody class appears to correlate more closely to clinical disease than IgG⁷.

immunofluorescent antibody testing, Sabin-Feldmann dye test, and agglutination tests. Although these tests are theoretically able to detect all classes of immunoglobulin against ''Toxoplasma gondii'' in many species, it seems that feline serum positive for IgM only often reads as a false negative^{5, 6} and so careful interpretation is necessary, particularly since the IgM antibody class appears to correlate more closely to clinical disease than IgG⁷. IgG antibody persists at high levels for at least six years after infection, and so a single IgG measurement is not particularly useful for clinical diagnosis. A rising IgG titre may be more suggestive of active toxoplasmosis: however, IgG is not produced until 2-3 weeks post-infection which may be too late to be useful in acute cases, and many animals with chronic toxoplasmosis will not be assayed until IgG is already at its maximal titre.

 

A more practically useful form of serology is examination IgM in aqueous humour or cerebrospinal fluid. Demonstration of an IgM titre of above 1:64 or a

demonstration of an increasing IgG titre can document

titre to the maximal IgG titre is approximately two to

from T gondii-naive kittens with antibodies in

recognition patterns between the queen and kittens.

 

* Demonstration of an IgM titre of above 1:64 or a

fourfold or greater increase in IgG titre, or the documentation

fourfold or greater increase in IgG titre, or the documentation

of local antibody production or DNA in aqueous

of local antibody production or DNA in aqueous