Cortisol binding capacity of corticosteroid binding globulin in hyperadrenocorticoid and healthy dogs.

Corticosteroid binding globulin (CBG) binding capacity and plasma cortisol concentration were determined in 27 dogs with hyperadrenocorticism and in 17 healthy control dogs. Cortisol concentrations were significantly higher in hyperadrenocorticoid dogs than in controls. CBG binding capacity did not differ between the two groups. It is concluded that excessive endogenous cortisol secretion does not induce an increase in CBG binding capacity. Consequently, the determination of CBG binding capacity provides no additional information for the diagnosis of canine Cushing's syndrome.

The effects of medroxyprogesterone acetate and ethinylestradiol on hemogram, prostate, testes, and semen quality in normal dogs.

Three dogs were treated with medroxyprogesterone acetate (MPA) and three were treated with ethinylestradiol. The results indicate that at a dosage of 3-4.8 mg/kg b.w. MPA does not have any detrimental effects on hemogram, testicles or semen quality, whereas ethinylestradiol (2 micrograms/kg b.w./day) can negatively affect both testes and semen quality. Both drugs can cause a decrease in prostatic size in clinically healthy dogs. Measurements of peripheral serum testosterone levels indicate that at the dosages used, testosterone levels are depressed considerably more by ethinylestradiol than by MPA.