Iris melanoma is the most common intraocular tumor in dogs. Distinguishing benign pigmented lesions from malignant melanoma guides welfare-appropriate treatment decisions.
Iris melanoma management requires careful welfare balance between preserving vision and preventing metastatic disease. Benign pigmented iris lesions — nevi, iris cysts, and diffuse iris pigmentation — require monitoring but not intervention. Malignant melanoma, identified through progression, secondary glaucoma, or tissue invasion, requires more aggressive management including enucleation when appropriate.
Secondary glaucoma from melanoma — elevated intraocular pressure from tumor blockage of aqueous humor drainage — causes severe pain that is the primary welfare driver for enucleation decisions. Dogs with painful glaucoma secondary to iris melanoma have better welfare post-enucleation than those maintained medically with persistent pain and pressure elevation.