Rapid Cellular Growth in Dogs

Histiocytic disease are a group of uncommon skin disorders which result from rapid and excessive growth of cells (medically known as cell proliferation). 

The disease occurs in young dogs with mean age of five years and of any gender. Skin disorder is not restricted to a particular disease but systemic disease –  where skin disorders spread into body systems –  are predominantely reported in Bernese mountain dogs.

The histiocytic disorders can be differentiated into cutaneuos histiocytosis, Malignant histiocytosis and Systemic histiocytosis. Common symptoms associated with each form include

Cutaneous histiocytosis

Lesions involve skin and are subcutis (in the deep connective tissue of the skin)

Multiple nodules or plaques on the head and neck, trunk, extremities, and scrotum

No systemic organ involvement

Often takes a fluctuating, chronic course, where spontaneous regression of lesions may occur

Malignant histiocytosis

Pallor, weakness, shortness of breath (dyspnea) with abnormal lung sounds, and neurologic signs (e.g., seizures, central disturbances, back leg weakness)

Moderate to severe enlargement of the lymph glands and enlargement of the spleen and liver

Masses occasionally found in the liver and/or spleen

Eyes and skin are rarely affected

Malignant form affects older dogs, at a mean age of seven years

Malignant histiocytosis is rapidly progressive and usually fatal

Systemic histiocytosis

Marked tendency for skin, and lymph nodes

Multiple cutaneous (outer skin) masses are nodular, well-defined, and often ulcerated, crusted or hairless around the mass (alopecic)

Commonly found on the muzzle, nasal planum (black area of the nose), eyelids, flank, and scrotum

Moderate to severe enlarged lymph glands (lymphadenomegaly) is often present

Eye manifestations

Abnormal respiratory sounds and/or nasal mucosa infiltration

Organomegaly (organ enlargement) occurs with systemic involvement

Systemic histiocytosis is a chronic and fluctuating debilitating disease with multiple clinical episodes and periods without symptoms

Other symptoms and types

Most commonly affects Bernese mountain dogs

Golden retrievers, flat coated retrievers, and rottweilers appear to be predisposed, suggesting genetic factors



Weight loss


Respiratory stertor (snoring sounds)

Dyspnea (shortness of breath)

Signs of systemic illness may not be present in dogs with cutaneous (skin) histiocytosis and in some dogs with systemic histiocytosis

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