Orbital Neoplasias - Dog and Cat
Primary orbital neoplasias are uncommon in dogs and cats.
Types Of Tumour
Meningioma is the most common primary tumour in dogs. It is a benign slow growing tumour that if untreated causes pressure atrophy.
Other tumours described include lymphosarcoma, adenocarcinoma, fibrosarcoma, multilobular ostersarcoma, glioma, myxoma, squamous cell carcinoma, rhabdomyosarcoma and canine lymphoid pseudotumour.
Clinical Signs
Unilateral, progessive and painless exopthalmos
Prominent and protruding third eyelid
Blindness, though not in all cases. This can help differentiate from glaucoma, which always causes blindness
Exposure keratitis, secondary to the exopthalmos
Retinal folds or retinal detachment on opthalmoscopic exam
Nasal discharge
Dilated/eccentric pupil
Treatment
Surgical exploration and removal of the globe and associated orbit contents is recommended.
Depending on the type of tumour chemotherapy or radiation therapy may be appropiate.
References
Maggs, D et al (2007) Slatter's Fundamentals Of Veterinary Ophthalmology (Fourth Edition) Saunders