We found lumps on Trey’s neck and had him examined. We suspect he has systemic histiocytosis – a reactive inflammatory diseases in which a disorder of immune system regulation is suspected. Histiocytosis is a cancer which proliferates rapidly and invade a wide variety of tissues. Histiocytes are a type of white blood cell called macrophages which ordinarily form part of the dog’s immune system. Their proper role is to engulf bacteria and other material which should not be present in the body and dispose of it. Histiocytosis is quite rare in other breeds but it is the most common cancer in Bernese Mountain Dogs comprising 25% of all cases.
Systemic histiocytosis can have episodes that come and go with varying severity. It invades the skin and peripheral lymph nodes in almost every case but also involves other tissues particularly in later stages of the disease. With systemic histiocytosis skin abnormalities are common, particularly on the face and limbs. If the tumor has metastasized to the lungs there may be trouble breathing. There are no successful treatments for histiocytosis at this time. It is simply a difference in how long the disease takes to run its course.
Trey’s surgery left him with stitches on his neck and left side. Below he models a t-shirt to keep him from scratching open the stitches. Since this picture we have found a turtle neck shirt which better protects his neck. With temperatures in the 70’s Trey is warm and uncomfortable, but the shirt is a necessity for another week.