When black or brown spots just seem to appear on the lips, nose, and eyelid margins of aging orange-colored cats, owners tend to worry. What are they and should you worry? The short answer is almost always no—they may look ominous, but they are harmless.
Why Do Orange Cats Have Black Spots?
The most common reason for these dark spots is lentigo simplex, a genetic condition that is most common in orange, calico, flame point, and tortoiseshell cats. Most often the spots (lentigines, which is plural for lentigo) appear in middle-aged to older cats, but they can occasionally begin in much younger cats.
Owners usually notice the small, dark spots on the lips or nose first, only to worry as more dots appear and some grow a bit larger. Cats may develop just a few or large numbers of lentigines.
What Are the Spots?
Small lesions may appear close together, discoloring a larger area. The lesions are flat, are not painful or itchy, and do not have any associated redness or other discoloration. If your cat has them on the face, it likely has them elsewhere as well, for instance, on the eyelids or the roof of the mouth.
The spots are the result of the pigment-producing cells called melanocytes making more melanin than the surrounding skin. It is thought that the gene that codes for orange coat color is unstable and reverts back to its more natural non-orange, dark gene over time. Cream- and silver-colored cats also occasionally have lentigo.
Lentigo Is Not Cancer
Rest assured: Lentigo is not a form of cancer, nor do lentigo spots advance to become melanomas. Lentigo is, in fact, completely harmless, like human freckles or age spots, and no medical treatment is necessary for the condition. That said, one cannot assume that every dark spot on your pet is harmless; this is just the most common scenario for orange cats. Lentigo can mask some melanomas, and raised darkened spots are more likely to be cancerous than flat spots. Have your cat checked out by your veterinarian to be sure.
It is always wise to check out any new finding with your veterinarian to rule out something serious, especially if the spots are at all raised, inflamed, or causing your pet discomfort. There are many conditions of the nose and lips that are more serious than lentigo. Your vet can provide a hands-on exam to guide your pet's care.
When to Worry About Black Spots
While lentigo is not a medical concern, cats do develop melanomas (a type of skin cancer), and it's important to know when a black spot is more than just a cat freckle. The most common form of melanoma in a cat (though it's still relatively rare) occurs in the iris (the colored part of the eye). Such tumors can look like dark patches on the iris, and usually occur in one rather than both eyes. Melanoma can also affect the skin and spread to other parts of the body as well.
While spots on the iris can be signs of cancer, they can also be benign; only your vet can make a qualified judgment on that issue. If you're concerned about a spot, lump or bump, or about your cat's overall health, a visit to the vet is in order.