Effect of the Oestrus Cycle on Coxofemoral Joint Laxity

Summary

A few investigations in the 1960’s were performed to document the effect of exogenous oestrogens on development of hip dysplasia. These projects concluded that oestrogen administration caused a significant increase in hip dysplasia. Additionally, the Orthopaedic Foundation for Animals (OFA) has recommended that bitches should not have hip evaluation for certification during oestrus, due to the possibility of increased coxofemoral joint laxity. The purpose of this project was to determine if physiological fluctuations of oestrogen and progesterone throughout 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 throughout the phases of the oestrus cycle, neither statistically nor clinically significant changes in coxofemoral joint laxity were documented.

A prospective study documented the effect of fluctuations of hormone levels throughout the oestrus cycle on coxofemoral joint laxity in nine dogs. Although oestrogen and progesterone levels changed significantly throughout the oestrus cycle, neither statistically nor clinically significant changes in hip laxity were observed.

Keywords

Oestrogen - progesterone - hip laxity - oestrus cycle - canine

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