Ka. Hassinger et al., EFFECT OF THE ESTRUS CYCLE ON COXOFEMORAL JOINT LAXITY, Veterinary and comparative orthopaedics and traumatology, 10(2), 1997, pp. 69-74
A few investigations in the 1960's were performed to document the effe
ct of exogenous oestrogens on development of hip dysplasia. These proj
ects concluded that oestrogen administration caused a significant incr
ease in hip dysplasia. Additionally, the Orthopaedic Foundation for An
imals (OFA) has recommended that bitches should not have hip evaluatio
n for certification during oestrus, due to the possibility of increase
d coxofemoral joint laxity. The purpose of this project was to determi
ne if physiological fluctuations of oestrogen and progesterone through
out the oestrus cycle significantly affected coxofemoral joint laxity.
Nine bitches were evaluated through a single oestrus cycle. Although
significant fluctuations of oestrogen and progesterone occurred throug
hout the phases of the oestrus cycle, neither statistically nor clinic
ally significant changes in coxofemoral joint laxity were documented.