Liver Standardization Project

The aim of the Liver Standardization Project is to obtain worldwide standardization for histological evaluation of liver tissues for liver diseases of dogs and cats: unified nomenclature, well-defined histological diagnostic criteria, and precise definition of chronicity stages and grades of diseases. Also, requirements for tissue staining techniques and size of tissue specimens are being recommended for the different diseases. Descriptions and typical slides of all relevant liver diseases of dogs and cats become available as a reference for all veterinarians. Of course liver diagnostics is not only a matter of histopathology. Therefore the relation with clinical and laboratory findings will be indicated when necessary. All this information will be published in a book, which will be available at an affordable price to make it widely available for all interested veterinarians and other potential users.

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This work was made possible by the generous sponsorship of Hills Pet Nutrition.

The Liver Study Group Members

The Group is made up of internationally recognized scientists in hepato-gastroenterology. In addition we have invited one of the top human liver pathologists.

Members are:

  • Dr. S. Bunch (USA), clinical hepatologist
  • Dr. J. Charles (Australia), liver pathologist
  • Dr. J. Cullen (USA), liver pathologist
  • Dr. V.J. Desmet (Europe, Belgium), human liver pathologist
  • Dr. T. van den Ingh (Europe, Netherlands), liver pathologist
  • Dr. T. VanWinkle (USA), liver pathologist
  • Dr. D. Twedt (USA), clinical hepatologist
  • Dr. R. Washabau (USA), gastroenterologist/hepatologist/ACVIM
  • Dr. J. Rothuizen (Europe, Netherlands), clinical hepatologist, coordinator of the Group.


Summary of work

In 2001, 2002, and 2003 the group has had five meetings in total. The diseases of the liver were grouped into vascular diseases, diseases of the biliary system (intra- and/or extrahepatic), cystic diseases, tumors of the liver and biliary system, and parenchymal hepatic diseases. Agreement has been reached about all these diseases. First, the concept was always presented at the ACVIM or ECVIM specialist congresses, and taking the comments into account, the final consensus was formulated the meeting thereafter.

The summary of the groups of diseases dealt with does not immediately show the enormous list of individual diseases and conditions that had to be discussed. For many diseases there were different names in use in the literature, which was very confusing. A unified name for all these diseases has been formulated so that readers in this field will be more comfortable. With the previous absence of standardised diagnostic criteria there has been much literature on a certain disease, which was in fact dealing with different diseases or at least a different spectrum of the same disease. It was therefore often impossible to compare results of research from different centres. A special field for which comparison of results from different centres will become of paramount interest is the multi-centre evaluation of treatments. In veterinary medicine there have been very few double blind, placebo-controlled and randomised studies on the effect of treatments, and the only way to include enough patients in such studies is by multi-centre studies. The availability of standards for liver diseases now makes this field of veterinary medicine ready for the start of such studies to build a science-based strategy for effective treatments.

Jan Rothuizen, March 2004



Final Outcome of the Liver Standardization Project

The work of the WSAVA Liver Standardization working group to develop a morphological liver disease classification scheme was completed during the ECVIM Meeting of September 2003, in Uppsala, Sweden. Subsequently, efforts have focused on the generation and eventual publication of this work. During this process, a decision was made to publish the work as a single entity, rather than multiple smaller articles. To this end, the groups collective work is now published in book format titled WSAVA Standards for Histological and Clinical Diagnosis of Canine and Feline Liver Diseases by Elsevier. A summary of the text and details of this book is provided on WSAVA publications page.



WSAVA Standards for Histological and Clinical Diagnosis of Canine and Feline Liver Diseases.  WSAVAs first textbook is on the shelves!
In a publishing partnership with Elsevier, WSAVA is proud to announce the availability of its first scientific textbook, titled WSAVA Standards for Histological and Clinical Diagnosis of Canine and Feline Liver Diseases, representing a culmination of efforts begun in 2000 and prompted by discussions between then WSAVA president Hans-Klaus Dreier, president-elect Claudio Brovida, and Dr. Jan Rothuizen of Utrecht University. Born from a WSAVA strategic initiative to strengthen the relationship between veterinary academia and veterinary medical associations, this project is the first in a series of standardization initiatives begun by the WSAVA in an effort to provide clear direction in areas of academic research that have a direct impact on the practice of veterinary medicine.

The authors involved are a veritable "who's who" of prominent, international researchers in veterinary hepatology and also includes one eminent human liver researcher (listed below). The textbook is designed to provide a world standard of guidelines for the diagnosis of liver diseases in dogs and cats using both histological and clinical criteria.

Chapters include:
•    Sampling and handling of liver tissue
•    Ultrasonographic identification and characterization of congenital portosystemic shunts and portal hypertensive disorders
•    Morphological classification of biliary disorders
•    Morphological classification of parenchymal disorders, including:
* Normal histology, reversible hepatocyte injury, and hepatic amyloidosis
* Hepatocellular death, hepatitis, and cirrhosis
* Hepatic abscesses and granulomas, hepatic metabolic storage diseases, and miscellaneous conditions
* Morphological classification of neoplastic disorders

This consolidation of international science and opinion regarding the diagnosis and staging of canine and feline liver disorders represents a critical step in elevating both the level of care provided by the veterinary profession for pet's suffering from liver disorders as well as ensuring that the common language proposed facilitates a greater degree of communication between researchers and ultimately, our understanding of these ailments.

For additional information and to order the book, visit the Elsevier website.

The WSAVA would like to recognize and thank Hill's Pet Nutrition for their generous sponsorship which made this work possible.