Congenital bilateral tibial agenesis with fibular bowing and limb deformity in a young kitten: a case report

Background: Complete agenesis, partial agenesis, or hypoplasia of a long bone may occur in domestic species. The radius, tibia, and ulna are most often affected, although the metacarpal, metatarsal, and phalangeal bones can also be involved. These anomalies, which can usually be detected at or shortly after birth, may be hereditary or result from in utero environmental factors. Radiographically, affected bones are conspicuously absent, and the limb is often shortened and malformed, with curvature and joint deformities. Methods: A ۴۵-days-old mixed-breed kitten with clinical signs of hind limb deformity and difficulty in walking was referred for radiographic evaluation of the limbs. Mediolateral and craniocaudal projections of both limbs were obtained under standard exposure parameters for neonatal patients. Results: Radiographs revealed complete agenesis of the left tibia, with marked cranial bowing and shortening of the left fibula. The stifle and tarsal joints were malformed, and the limb appeared shortened with angular deformity. On the right side, partial agenesis of the tibia at the distal segment was observed, consistent with partial tibial agenesis rather than hypoplasia. The right fibula was continuous but deformed, showing a similar bowing pattern. All long bones exhibited mild generalized decreased opacity, consistent with disuse osteopenia. Mild stifle joints swelling was present, bilaterally. The pelvis, femur, and vertebral column were unremarkable. Conclusion: Tibial agenesis in feline is considered a very rare anomaly. This case represents bilateral tibial agenesis, complete on the left and partial on the right. Due to severity of the malformations, no treatment was instituted. Accurate differentiation between agenesis and hypoplasia is essential for prognosis and management.

کلیدواژه ها:

Kitten ، Tibial agenesis ، Partial tibial agenesis ، Fibular bowing ، Congenital limb deformity