Androgens and estrogens accelerate physeal closure by allowing calcium deposition at the physes. In cats, physes have been shown to close at 4–9 months of age, but studies have shown delayed closure secondary to early neutering. This retrospective study sought to further establish this database, focusing on several pelvic limb physes, with a hypothesis that male and female neutered cats would have open physes at a later age than do intact cats.
Pelvic and femoral radiographs (n = 783) of cats were evaluated for physeal closure at the greater trochanter, proximal femur, distal femur, and proximal tibia. Date of birth, gender, breed, and neuter status were recorded, but age at time of neuter was not available.
The only significant differences noted were later closure in neutered males, as compared with intact males, at the greater trochanter, distal femur, and tibial tuberosity. No significant differences were found in female cats at any physis. Clinical consequences should be further evaluated.
