Developing coxal joint of the dog: gross morphometric and pathologic observations

Area of Science:

• Veterinary Anatomy
• Comparative Osteology
• Canine Hip Development

Background:

• The proximal femur and acetabulum are critical components of the canine coxal (hip) joint.
• Understanding their growth patterns is essential for identifying developmental abnormalities.

Purpose of the Study:

• To document the linear growth of the proximal femur and acetabulum in English Pointers from birth to 9 months.
• To correlate age with morphometric changes and the onset of pathological alterations in the coxal joint.

Main Methods:

• 32 English Pointers were grouped by age (birth to 9 months).
• Necropsy included 6 linear measurements of the proximal femur and 7 of the acetabulum.
• Other coxal joint features (capsule thickness, ligament integrity, surface regularity) were assessed.

Main Results:

• Femoral head and acetabular dimensions increased rapidly in the first 4 weeks, then slowed.
• Body weight increased 52-fold, while femoral head and acetabular diameters increased 4.5-fold by 9 months.
• Pathological changes in coxal joints were absent in young dogs but present in 1/6 at 5 months, 2/6 at 7 months, and 4/6 at 9 months.

Conclusions:

• Canine proximal femur and acetabulum exhibit significant, proportionate growth, primarily in early life.
• Age-related pathological changes in the coxal joint become increasingly prevalent from 5 months onwards in this cohort.