Serum samples from 185 chickens (Gallus gallus) collected from the var
ious slaughter markets in and around Madras City, India were examined
for antibodies to Toxoplasma gondii using the modified agglutination t
est incorporating mercaptoethanol. Antibodies (greater than or equal t
o 1:25) to T. gondii were found in 39.5% of sera. Antibody titers of i
ndividual sera (% in parentheses) were 1:25 (8.1%), 1:50 (10.8%), 1:10
0 (6.5%), 1:200 (2.7%), 1:400 (4.3%), 1:800 (5.9%) 1:1,600 (0.5%), and
1:3,200 (0.5%).