EFFECTS OF AGE, SEX, REPRODUCTIVE STATUS, AND HOSPITALIZATION ON SERUM ALPHA(1)-ANTITRYPSIN CONCENTRATION IN DOGS

We performed a study to determine a reference range for serum alpha(1) -antitrypsin (alpha(1)AT) in dogs by specific immunoassay; to evaluate whether serum alpha(1)AT concentration varied with age, sex, or repro ductive status in healthy dogs; and to investigate whether the serum a lpha(1)AT concentration in hospitalized dogs differed from that of hea lthy, nonhospitalized dogs. Serum alpha(1)AT was quantitated by radial gel immunodiffusion for 60 healthy dogs and 311 hospitalized dogs. In healthy dogs, serum alpha(1)AT concentration was 2.33 +/- 0.41 mg/ml (mean +/- SD), yielding a reference range (mean +/- 2 SD) of 1.51 to 3 .15 mg/ml. A correlation was not found between serum alpha(1)AT concen tration and age in healthy dogs. The serum alpha(1)AT concentration (m ean +/- SEM mg/ml) was significantly higher in healthy, sexually intac t females (2.64 +/- 0.1) than in healthy, spayed females (2.22 +/- 0.1 2; P < 0.004); healthy, sexually intact males (2.14 +/- 0.1; P < 0.000 6); and healthy, castrated males (2.25 +/- 0.14; P < 0.02). Hospitaliz ed, sexually intact females had a lower serum alpha(1)AT concentration (1.93 +/- 0.07) than healthy, sexually intact females (2.64 +/- 0.1; P < 0.0002). Likewise, the serum alpha(1)AT concentration in hospitali zed, sexually intact males (1.92 +/- 0.04) was less than in healthy, s exually intact males (2.14 +/- 0.1; P < 0.04). A difference in alpha(1 )AT concentration was not found between healthy and hospitalized, neut ered dogs.