Surgical and Conservative Management of Periorbital Tumors in Four Dogs.

Four client-owned dogs with histopathologically confirmed periorbital tumors were included in this retrospective case series: one spayed female, one intact male, and two neutered males. The dogs ranged in age from 6 to 8 years. The most common clinical signs were slowly progressive exophthalmos (4/4 dogs), epiphora (3/4 dogs), and prolapse of the nictitating membrane gland (2/4 dogs). Periorbital disease was initially suspected based on the clinical examination. Computed tomography (CT) was subsequently used to characterize the presence, location, and extent of the lesion and for surgical planning, whereas histopathological examination confirmed the tumor type. The identified tumors included two multilobular tumors of bone (MTB), one inflammatory myofibroblastic tumor (IMT), and one sebaceous carcinoma (SC). Treatment for the first three dogs consisted of wide tumor excision via combined modified lateral orbitotomy and partial ostectomies of the zygomatic arch and mandibular ramus. The remaining dog received conservative therapy. For the first two surgically treated dogs, survival times were 55 months; the third dog was lost to follow-up two weeks after surgery. For the conservatively treated dog, the survival time was 4 months. Although limited by the small number of heterogeneous cases, this report suggests that the described surgical approach facilitated en bloc excision in these three surgically treated dogs. However, histologically tumor-free surgical margins were confirmed in only one of the three surgically treated dogs, and clinical outcomes varied according to tumor type, extent of disease, and duration of follow-up. Therefore, further studies are required before definitive conclusions regarding oncologic outcome or prognosis can be drawn.