Fig. 4
Serum (A; C) and saliva (B) cortisol in S. suis cps3 infected piglets with or w/o buprenorphine treatment. A + B Serum and saliva of buprenorphine-treated (n = 5) (■) and untreated (n = 5) (●) piglets were taken before (pre inf) and at the indicated times after infection with 2 × 108 CFU of S. suis cps3 strain 16667/3 to determine serum (A) and saliva (B) cortisol levels. As indicated, one group was treated i.m. with 0.05 mg/kg buprenorphine every 8 h 0 to 5 days post infectionem (dpi). Prematurely euthanized piglets with clinical signs of severe disease were excluded in A and B. One untreated piglet which showed clinical signs of S. suis disease had very high serum cortisol level (> 40 ng/ml) 2 dpi (A) and additionally high saliva cortisol levels (> 5 ng/ml) 1 dpi (B). The buprenorphine-treated piglet with the highest cortisol saliva level (> 10 ng/ml) was morbid on the 1st dpi, but showed prominent recovery thereafter. C Comparison of serum cortisol levels of clinically healthy (n = 10) and mortally ill (n = 6) piglets infected with 2 × 108 CFU S. suis cps3 and sampled under anaesthesia prior euthanasia. The serum of clinically healthy piglets was collected 13 dpi, whereas in mortally ill piglets, final serum samples were collected within 1–2 dpi after reaching predefined humane endpoints. Mean values are indicated by horizontal lines, standard deviations by error bars. Statistical analysis was conducted with the Mann–Whitney-U-test (comparison of groups). Significances are indicated (* p < 0.05, ** p < 0.01)