Differential Diagnosis include: 1. Haemangioma (usually looks like a blood blister) 2. Melanoma (usually black but can be amelanotic) 3. Limbal melanocytoma (smooth black swelling arising at the limbus) 4. NGEK Nodular granulomatous episcleriokeratoconjunctivitis (pale pink to cream-coloured swellings)
Conjunctival Haemangioma/Haemangiosarcoma - These tumours are seen most commonly in middle-aged Kelpies, Border Collies and Aust. Cattle Dogs. They are thought to be secondary to UV exposure and are usually situated in the conjunctiva adjacent to the lateral limbus. In the earliest form it may appear as swollen blood vessels and hyperaemia and may respond to topical cortisone drops. Once they are blood-blister-like in appearance, surgery is required. Excision of the mass with 3-5mm margins and cryotherapy is usually curative.
They do not appear to be related to haemangiosarcoma seen elsewhere in the body. Malignancy at pathology (i.e. sarcoma vs haemangioma) is not associated with poorer treatment outcomes.
In all cases of conjunctival mass surgery, the cut edges of the conjunctiva must be sutured to the sclera. Cortisone tablets are used post-operatively to treat possible uveitis associated with cryotherapy and the eye is checked at 1-2 weeks. Owners are advised to monitor the eye daily for signs of uveitis. Cortisone drops are used once healing is complete to reduce hyperaemia/scar tissue.
In all cases, clients must be warned to monitor for recurrence as early treatment will result in more complete excision and favourable outcome.