What should you know about canine iris melanoma?

The iris is the coloured ring that controls the pupil. A dark spot, diffuse colour change, uneven pupil, redness or cloudy eye can arise from several causes, including inflammation, bleeding or a tumour. Appearance alone cannot confirm melanoma. The veterinarian may examine the eye with specialised equipment, measure eye pressure and assess vision, then discuss monitoring, sampling or removal. Melanoma is the wider condition; an iris mark is not automatically cancer. Some tumours can affect nearby structures or spread, so the examination also considers the rest of the animal.

Arrange an eye examination promptly, particularly if the mark is enlarging or the pupil is changing. Take clear photographs in consistent light to show progression, but do not delay care while comparing images. Prevent rubbing with a protective collar if advised and use only prescribed eye medicines. Depending on the size, position, pressure and vision, options may include observation, Surgical Excision, Skin Cancer Surgery or Tumour Removal Surgery. A specialist may explain whether Sentinel Lymph Node Biopsy or other staging is relevant; eye surgery has specific effects on vision and appearance that should be discussed.

Seek same-day veterinary help for squinting, severe eye pain, sudden vision change, a bulging eye, marked redness, bleeding, cloudiness, a fixed or very uneven pupil, or repeated rubbing. New weakness, seizures or other neurological changes are also urgent because distant spread, including Brain Metastases, must be considered alongside other causes. If melanoma is confirmed, ongoing Follow-Up After Cancer Treatment may be recommended. Immunotherapy is a specialist discussion rather than a treatment to begin without a diagnosis.

Ask whether the lesion is affecting pressure or vision, what tests can distinguish tumour from inflammation, which treatment preserves function, and how often the eye should be rechecked.