The most common clinical sign of a malignant mammary tumor is one (or more) palpable masses underneath the skin of the abdomen. They may be next to or within the nipple and follow along the mammary chain (see illustration). The size of the mass(es) and their appearance may vary, but they are usually firm and nodular.
A mammary tumor is a tumor of the mammary tissue. They are common in un-spayed dogs and dogs spayed after their first heat cycle. Mammary tumors occur more frequently in breeds such as toy and miniature poodles, spaniels and German shepherds. Male dogs are rarely affected.
What causes mammary tumors in dogs? Mammary tumors develop because of spikes in female hormone (estrogens) that take place during a dog's heat cycle. By spaying a dog at 6 months of age or before the first heat cycle, it virtually eliminates the risk of getting mammary tumors, which starts at only about 0.5%.
Basal cell tumors can take on many forms, including a pearly white or waxy bump, often with visible blood vessels, on the ears, neck, or face. Tumors can also appear as a flat, scaly, flesh-colored or brown patch on the back or chest, or more rarely, a white, waxy scar.
Lipomas often form in the fatty tissue under the skin. These are also the most noticeable ones, as they look and feel like soft, dome-shaped lumps under the skin. They vary in size from pea-sized to several centimetres in diameter.
Lipomas: These are the most common skin tumors of dogs. They feel like soft, fleshy lumps that are typically hemispherical or round. The deeper ones can feel firmer and scarier, but they're almost always benign too. Skin tags: These benign masses look like tiny, often elongated outcroppings of skin.
Palpation (feeling with the fingers) of the scrotum may reveal a nodular enlargement of the testicle, unevenly sized testicles, or generalized swelling of the scrotum. "Most dogs with testicular tumors do not have any obvious clinical signs.
A lipoma will typically present initially as a small, hemispherical lump under a dog's skin. It will usually appear haired, relatively soft and somewhat mobile, though variations in texture (firmer masses that are more firmly adhered to the underlying tissues) are not uncommon.
The cutaneous papilloma in dogs is benign and of non-viral origin. This tumor is more common in older canines. This tumor is a whitish-gray color and is shaped similar to that of a cauliflower. They are generally located on the head, feet, and eyelids.
Melanomas appear pigmented or non-pigmented, and may be nodular or cauliflower-like in appearance. These tumors may appear as swellings on the gums around the teeth or on the hard or soft palates. They frequently ulcerate (break open) and bleed. They may also become infected.
In the case of benign perianal adenomas, you many see one or more small, round, pink, hairless, slow-growing nodules around the anus. Although they usually grow around the anus, they can grow in the prepuce, scrotum, and under the tail.
Benign or malignant tumors of the earwax glands (called ceruminous glands) can develop in the external ear canal.. These tumors can appear as smooth or bumpy stalk-shaped lumps or flattened patches that rise off the lining of the ear canal. A deep biopsy of the tissue is necessary for diagnosis.
These tumors, whether benign or malignant, will change the appearance of your dog's eye. With melanoma of the iris, you may see one or more roughly circular brown or black spots (lesions) on the iris. They may be flat or raised and may grow over time to become discrete, raised pigmented masses.