A neutered male Domestic Shorthair cat was seen by Dr. Kinnunen because he had a strange swelling on his ventral abdomen that had a couple of red areas and a point in the middle. An aspiration and cytology revealed white blood cells and red blood cells. It did not seem painful to the cat. Surgical removal was scheduled 2 days later.
A wide excision of the area was made. Inflammation extended all the way to the underlying muscle. Dr. Freesh did the surgery and started removal at the front of the incision (towards the head) removing all of the subcutaneous tissue from the muscle. About midway she saw a brown 1-2 mm diameter object extending from the fat to the muscle. The entire area was excised, subcutaneous sutures placed, and the skin stapled closed. See the photo of the stapled area after surgery. A penrose drain tube was placed because of suspected infection. The brown foreign body was pulled out. It was about an inch long. It may be a splinter, twig, or something else wooden.
Foreign bodies can be anything that penetrates the skin and works it's way into the body. It is not part of the body; so the body reacts by producing granulation tissue to wall it off and sends white blood cells to kill an infection. The area cannot heal until the foreign body is removed.
Dr. Freesh found a small thorn in a huge granulation mass on the side of a Labrador Retriever many years ago. It was just luck that she found the thorn because it was so small. The dog healed up great after that. Over the years, Dr. Freesh has removed some interesting things from draining tract areas in cat digits. One looked like a piece of paper that was folded into a tiny tube. It opened up into a surprisingly larger piece of a thin material that appeared to be paper. The owner and Dr. Freesh could never figure out how that happened.
When Dr. Freesh lived and worked in Wisconsin, dogs frequently had penetrating fox tails under the skin or some would burrow into the abdominal or thoracic cavities.
Foreign bodies can be found in eyes and a pet's mouth also.