Public Overview


DVM Overview


Histiocytic lineages


Dendritic cell migration

Histiocytoma Complex


Cutaneous LCH

Histiocytic Sarcoma Complex

General Considerations

Histiocytic Sarcoma Complex

Distinctive Syndromes

- Hemophagocytic HS

- Articular / periarticular HS


- Dendritic cell leukemia

K9 Reactive Histiocytoses

RH - General

Cutaneous Histocytosis

Systemic Histocytosis

RH vs Inflamed lymphoma

Feline Prog. Histiocytosis

Feline Pulmonary LCH




Welcome to the Histiocytosis Site


This site was developed to provide a current information source for pet owners, clinical veterinarians and pathologists who wrestle dissecting the intricacies of diagnosis, prognosis and treatment of the spectrum of histiocytic proliferative diseases in dogs and cats.


The site is geared toward both the pet owner and the professional. For the pet owner there is an overview of histiocytic diseases and a frequently asked questions (FAQ) discussion where many of your questions may have been answered. For the professional (and interested pet owner) there is a more technical overview of histiocytic diseases and a detailed, illustrated description of the individual histiocytic diseases.


I hope you find this site of use in clearing up doubts, misinformation and in dealing with the frustration of histiocytic disease. I would like to thank the Institute for Genetic Disease Control for arranging the financial support for the initial development of this site. The site was extensively revised in early 2016 to better align with the review paper published in Veterinary Pathology in 2014 (“A Review of Histiocytic Diseases of Dogs and Cats” P. F. Moore, Veterinary Pathology 2014, 51 (1):167-­184). Accordingly, histiocytic diseases of cats have been added; most of these were described after the original site was posted in 2002.



Peter F. Moore

Professor VM Pathology, Microbiology and Immunology

School of Veterinary Medicine

University of California

Davis, CA 95616



The author retains copyright of all images within this site. Images may be used for teaching purposes with permission and appropriate acknowledgement.