Yes, dogs have a xiphoid process. It’s the small, flat piece of bone and cartilage at the very bottom of the sternum (breastbone), and it’s completely normal. If you’re reading this, you probably felt a firm lump or bony protrusion on your dog’s chest and wanted to know what it is. In most cases, that’s the xiphoid process, and it’s nothing to worry about.
Where the Xiphoid Process Is Located
A dog’s sternum is made up of eight individual bones called sternebrae, connected by cartilage joints. The xiphoid process is the very last of these bones, sitting at the tail end of the breastbone where the ribcage ends and the soft belly begins. It’s flat and long, and sometimes has a small natural hole (foramen) in its back half.
The bony part of the xiphoid extends further as a flap of cartilage called the xiphoid cartilage. This cartilage supports the front part of your dog’s belly wall and connects to the linea alba, the tough strip of connective tissue that runs down the center of the abdomen all the way to the pelvis. Because part of it is cartilage rather than bone, it won’t show up on X-rays. Only the mineralized bony portion is visible on radiographs.
What It Does
The xiphoid process serves as an anchor point for the diaphragm, the large sheet of muscle that separates the chest cavity from the abdomen and powers breathing. It doesn’t have many other direct muscle attachments. Instead, it acts more as a structural hub: the connective tissue of the abdominal wall muscles merges with the fascia of the deep chest muscles right at the xiphoid, tying the chest and abdominal walls together.
Veterinarians also use the xiphoid process as a physical landmark. During abdominal procedures, the xiphoid marks the top boundary of a midline incision, with the pelvis marking the bottom. It’s easy to feel through the skin, which makes it a reliable reference point.
Why You Can Feel It
The xiphoid process often becomes noticeable when a dog lies on its back or when you run your hand along the underside of the chest. In lean or thin dogs, it can stick out quite prominently and feel like a hard lump. This is especially true in puppies and young dogs, where the surrounding cartilage is still soft and the bony tip is more exposed.
Weight changes can also make a difference. A dog that has recently lost weight may suddenly have a more obvious xiphoid simply because there’s less fat and tissue covering it. Deep-chested breeds like Greyhounds, Boxers, and Dobermans tend to have more palpable xiphoid processes because of their body shape, though every dog has one regardless of breed or size.
The angle of the xiphoid can vary from dog to dog. In some, it points slightly outward or downward, making it feel like a bump. In others, it sits flush against the body and is barely noticeable. Both are normal variations.
When a Lump Isn’t the Xiphoid
The key characteristics of a normal xiphoid process are its location (dead center at the bottom of the ribcage), its firmness (it feels like bone, not soft tissue), and the fact that it doesn’t change in size over days or weeks. It shouldn’t be painful when you press on it, and there shouldn’t be swelling, redness, or heat around it.
A lump worth investigating would be one that’s growing, feels soft or movable under the skin, sits off to one side rather than on the midline, or causes your dog pain when touched. Fatty tumors (lipomas) are common in dogs and can appear in the chest area, but they feel distinctly different from bone. They’re soft, round, and slide under the skin when you push them. A hard swelling directly over the xiphoid that seems larger than expected could, in rare cases, indicate a fracture or displacement, though this typically follows obvious trauma like being hit by a car or a significant fall.
If the lump you’re feeling is right on the midline, hard, and roughly the size and shape of the tip of your finger, you’re almost certainly feeling normal anatomy. If anything about it seems off, a quick veterinary exam can confirm what you’re dealing with.