CONCENTRATIONS OF TOTAL SERUM IGE, IGA, AND IGG IN ATOPIC AND PARASITIZED DOGS

Concentrations of total serum IgE, IgA, and IgG were measured in 36 at opic and 16 parasitized dogs, and compared them with 30 healthy contro l dogs. IgE was measured using enzyme-linked immunosorbent assay. IgA and IgG were measured using radial immunodiffusion assays. Mean total serum immunoglobulin (Ig)E concentrations in healthy, atopic and paras itized dogs were 7.1 units (U) ml(-1), 5.8 U ml(-1) and 14.3 U ml(-1), respectively. Mean total serum IgA concentrations in the same groups were 103.3 mg dl(-1), 63.2 mg dl(-1) and 67.3 mg dl(-1), respectively. Mean total serum IgG concentrations were 1066 mg dl(-1), 1621 mg dl(- 1) and 1480 mg dl(-1) in the three groups. There was no significant di fference in IgE concentrations between these groups of dogs. IgA level s were significantly lower in atopic and parasitized dogs compared wit h healthy dogs (P less than or equal to 0.05), whereas IgG levels were significantly higher in the atopic and parasitized dogs (P less than or equal to 0.005). These results suggest that measurement of total se rum IgE would be of no benefit in the preliminary clinical investigati on of a suspected atopic dog. The lower IgA and higher IgG concentrati ons in both atopic and parasitized dogs suggest that similar regulator y mechanisms governing immunoglobulin synthesis occur in canine allerg ic and parasitic disease, promoting IgG synthesis but down-regulating IgA production.