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This information is provided by Provet for educational purposes only.

You should seek the advice of your veterinarian if your pet is ill as only he or she can correctly advise on the diagnosis and recommend the treatment that is most appropriate for your pet.

Melanoma of the eye occurs in both cats and dogs, but there are some significant differences between these tumours in the two species.

The main differences between melanoma of the eye in cats and dogs are as follows :

Frequency of occurrence Uncommon Uncommon - but it is the most common intraocular neoplasm in dogs
Most common site Iris (anterior face usually) Iris (anterior surface) or ciliary body (difficult to see in early stages).
Most common form Diffuse infiltrate Raised nodule
Color Brown usually Brown to black
Rate of growth Often very slow. It can take months-years before secondary effects develop. Slow
Secondary effects Glaucoma. Corneal oedema, glaucoma, lens luxation
Predisposed breeds   German Shepherd Dogs, Labrador Retrievers
Genetic inheritance   Possibly
Metastatic spread High - 30-60% spread Usually less than 5% spread post-enucleation follow-up.
Treatment Enucleation. Laser treatment? Enucleation. Surgical resection occasionally. Laser treatment ?
Differential diagnosis Melanosis of the iris in middle-aged cats can be difficult to differentiate.  
Metastasis Radiograph chest for secondary spread  Radiograph chest for secondary spread