Metabolism of estradiol in greyhounds and German shepherd dogs. An investigation with special reference to hip dysplasia.

Metabolism of estradiol was investigated in 5 dogs, 3 female Greyhounds with radiographically perfect hip joints and 2 female German Shepherd dogs with hip dysplasia (one pregnant and the other non-pregnant). One of the Greyhounds was studied both when pregnant and non-pregnant. The non-pregnant dogs were injected with C14-labelled estradiol-17beta i.v. and 5 mg estradiol-17beta benzoate i.m. The pregnant dogs were given only radiolabelled estradiol-17beta. Twenty-four-hour-specimens of urine were collected from the dogs for 6--8 days. Determination of urinary estrone, estradiol-17beta, and estriol was made. It was found that most of the injected estradiol was excreted unmetabolized in all dogs. A significant amount of the injected estradiol was converted to estrone and a small amount to estriol. There was no significant difference in the excretion patterns of estrone, estradiol, and estriol between the Greyhounds with perfect hip joints and the German Shepherds with hip dysplasia, regardless whether the dogs were pregnant or not. The conclusion was drawn that the capacity of dogs with hip dysplasia to metabolize estradiol and to eliminate estradiol and metabolites is not impaired.