Tumors develop when cells in the body grow uncontrollably. Finding a tumor on your dog can be very frightening, but they are not always detrimental — some are benign, while others are malignant.

Meera Pal is a Northern California-based writer with a background in journalism and books. She covers pets, real estate, tech, and everything in between. You can follow her on Twitter @Meerakat Kelly ...

Q: I recently adopted Missy, my mother’s middle-aged, mixed-breed dog. She was never spayed, and she has two small masses in her mammary glands. Are these masses likely to be cancer? If not, should I ...

A study found that meningiomas — the most common type of brain tumor in humans and dogs — have similar genetic makeup Nicholas Rice is a Senior Editor for PEOPLE Magazine. He began working with the ...

Estrogen's role in canine mammary cancer is more complex than previously understood, according to new research. The nuanced findings may help explain why dogs spayed at a young age are more likely to ...

Researchers have found a very high prevalence of Bartonella bacteria in tumors and tissues - but not blood samples - taken from dogs with hemangiosarcoma, a cancer of the blood vessels. Researchers ...

Lipomas are the most common benign skin tumors of dogs, which are most frequently found in middle-aged and overweight animals. The small, soft, movable lumps that originate below the skin usually grow ...

A lipoma is a benign (noncancerous) tumor of fat in middle-aged or older dogs. Lipomas can grow anywhere on the dog's body, even inside their abdomen. But the most common growth is under their skin ...