Use of a microtiter Coombs' test for study of age, gender, and breed distributions in immunohemolytic anemia of the dog.

Sixteen of 17 dogs with immunohemolytic anemia had a microtiter Coombs' test titer greater than or equal to 1:64. Performance of the test as a hemagglutination assay apparently increased the sensitivity of the test. Three of the dogs with immunohemolytic anemia were sexually intact females, 11 were spayed females, and 3 were sexually intact males. When age and gender were considered together, females were 4.3 times more likely to have immunohemolytic anemia than were males (P less than 0.05). When corrected for population age distribution, spayed females were not predisposed to the problem.