Percutaneous doxycycline sclerotherapy in a horse with a mandibular aneurysmal bone cyst.

Objective: To describe the use and outcome of sclerotherapy with intralesional doxycycline foam in a horse with a mandibular aneurysmal bone cyst.

Study design: Case report.

Animals: Client-owned 1 year old Standardbred filly.

Methods: The horse presented for progressive mandibular swelling. A 10 mg/mL doxycycline foam was prepared for intralesional injection. Three doses were injected into the lesion under computed tomographic guidance at 6 and 15 weeks after initial treatment. Volume reduction was monitored after each treatment with 3D volumetric rendering and region of interest segmentation using commercially available software.

Results: The volume of the lesion decreased from 458.7455 cm³ before treatment, to 363.3101 cm³ at 6 weeks, 273.5855 cm³ at 15 weeks, and 247.2316 cm³ 6 months later, resulting in a total reduction of 54% of the initial volume. Bone formation was noted in the lesion. No adverse effects related to doxycycline foam injections were noted. The mandibular swelling was resolved after treatment.

Conclusion: Intralesional doxycycline sclerotherapy was shown to be efficacious in reducing the volume of the aneurysmal bone cyst in the horse presented in this report. There was complete resolution of mandibular swelling with no side effects related to the intralesional injections.