• Introduction
• Overview
• Session 1: Background to FCoV/FIP
• Session 2: Diagnosis & Treatment of FIP
• Session 3: Epidemiology of FCoV Infection
• Session 4: Pathogenesis and Immunopathogenesis of FIP
• Session 5: Prevention of FCoV Infection/FIP
• Workshop Results
• Glossary

Susan Little, DVM, Dipl. ABVP (Feline), Winn Feline Foundation
Janet Wolf, Executive Director, Winn Feline Foundation

Edited by Al Legendre, DVM, PhD., University of Tennessee
Copy editing by David Frost, Myanmar Birmans

INTRODUCTION

Dr. Diane Addie, University of Glasgow, Conference Chair, Welcoming attendees to 2nd International FIP Conference.

In August 2002, the 2nd international veterinary conference on feline coronavirus (FCoV) and feline infectious peritonitis (FIP) was hosted by Drs. Diane Addie, Oswald Jarrett, and Margaret Hosie of the University of Glasgow, Scotland. It had a number of co-sponsors including the Winn Feline Foundation and the Center for Companion Animal Health (CCAH) at the University of California (Davis). Winn and CCAH were the coordinators of the first conference, held in August of 1994. Feline coronavirus researchers from around the world met in Glasgow for three days to share their results, explore new avenues for research, and develop new working relationships. The Winn Feline Foundation anticipates for our next grant cycle an increase in proposals to research this complex and frustrating disease.

A fascinating mix of people met in Glasgow, including the head of the Cats Protection League of Great Britain, representatives of pharmaceutical companies and leading researchers from Switzerland, Austria, Australia, Germany, Great Britain, Sweden, the United States, The Netherlands, Hungary, Poland, South Africa, and Japan. Many of the participants also attended the first conference eight years ago. Significant progress has occurred since 1994, although there is still no way to prevent coronavirus infection, or an effective treatment for FIP.

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OVERVIEW:

At the first conference, the groundbreaking use of the polymerase chain reaction (PCR) technique represented a major step forward in research. At this conference, it was evident that PCR is now in use around the world to better understand feline coronavirus infection and feline infectious peritonitis. Currently coronavirus research includes production of genetically engineered coronaviruses, use of different viral vectors (such as spumavirus and poxvirus) for new vaccines, and the development of DNA vaccines. Researchers presented their findings on new diagnostic aids for FIP, such as cytokine profiles, measurement of acute phase proteins, and detection of virus within blood cells. Preliminary data was presented on the efficacy of recombinant feline interferon for the treatment of FIP.

Significant studies were done on cats in shelters and catteries. Dr. Niels Pedersen's group assessed the disease state of cats entering a shelter, and the changing antibodies and viral shedding patterns over the next two to three weeks. The information they obtained increased our basic knowledge of feline coronavirus and other feline infectious diseases. A much higher number of animals than predicted showed antibodies to FCoV during the initial screening (35% in shelters compared to 40%-80% in most catteries). After one week in the shelter, the number of cats testing positive for coronavirus had almost doubled. Those that had tested positive initially showed an increase 100 to 1,000 times the amount of virus shed in the stool by the end of the first week. Kittens demonstrated a disproportionately higher coronaviral load in feces than did older cats. However, in this study, no kittens under 8 weeks of age were infected on the initial screening. Kittens between 8 and 23 weeks of age had the highest rate of viral shedding. At about one year of age, the production of coronavirus decreased significantly.

A recommendation from the first International FIP/FECV Workshop in 1994 was to isolate queens with their kittens and to early wean at 6-8 weeks of age. Research conducted at the University of Glasgow showed that kittens raised in isolation with their mothers could remain seronegative for coronavirus until 6-8 weeks of age. Dr. Diane Addie and Dr. Danielle Gunn-Moore continue to have success with this strategy. However, a Swiss study conducted in catteries by Dr. Hans Lutz, with isolated kittens showed viral fecal shedding as early as 2 weeks of age. By 6 weeks of age, 50% of the kittens were shedding virus. Since the kittens had already been exposed to coronavirus, there was no reason to early wean. In looking at fecal shedding patterns, Dr. Lutz concluded that PCR analysis of fecal swabs must be done over a period of at least 4 weeks to accurately assess the viral load in any given cat or kitten.

Dr. Diane Addie looked at the patterns of FCoV shedding in naturally infected cats. Shedding of feline coronavirus in the saliva of these cats occurred only briefly and often before they had become seropositive for coronavirus antibodies. This result was confirmed by Dr. Lutz's cattery-based study. In following these cats, Dr. Addie learned that most shed coronavirus for 2-3 months and she found that intermittent shedding of virus was common. Therefore, a single PCR analysis is not sufficient to determine the FCoV status of a cat. In her study, about 13% of the infected cats became viral shedders for life. Only a small proportion of the cats in her study eventually died of FIP.

From the studies presented, recommendations for minimizing disease spread in multi-cat situations were developed in a workshop. Under some circumstances, isolation and early weaning are still valid. However, early weaning can sometimes create behavioral problems in kittens as well as difficulty in weaning. If your cattery/shelter has never had a problem with FIP, then it may not be necessary to change your current practices. Even without early weaning, the workshop recommended that queens be isolated two weeks prior to their delivery date. Queen and kittens should be kept isolated from other cats in the shelter or cattery. If the kittens are shedding virus as detected by PCR on feces or are seropositive for FCoV by 6-8 weeks of age, there is no need to wean early. They should, however, remain separated from the rest of the colony.

A significant challenge remains the availability of reliable and affordable tests. There are currently no standards for coronavirus antibody testing and there is significant variability in test results depending on the commercial laboratory that is used, especially in the United States. Several of the universities conducting research, including the University of Glasgow and the University of California (Davis), also have coronavirus antibody tests available. Dr. Diane Addie reported on one in-office test kit (Immunocomb®) marketed by Biogal Galed Labs, a company from Israel. She evaluated the kit against a standard immunofluorescence antibody test (IFA) used in her own laboratory and found a high degree of correlation. Unfortunately, it is not anticipated that Immunocomb® will be available in the United States.

A consensus developed that a third international conference should be convened in about three years. This year's conference demonstrated that there is a highly dedicated group of researchers working to unlock the secrets of the feline coronavirus. Future aims are to improve diagnostic tests and to develop treatments and vaccines.

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The Winn Feline Foundation is a non-profit organization established by the Cat Fancier's Association, Inc. to support health-related studies benefiting cats. Winn is exempt from Federal Income Tax under Section 501(c)(3) of the Internal Revenue Code. Accordingly, contributions to the Foundation are deductible for Federal income, gift and estate tax purposes.

NOTE: The Winn Feline Foundation unfortunately is not staffed to provide medical information or assistance on an individual basis. Your own veterinarian is your best source for feline health information.

Please email comments to Winn@WinnFelineHealth.org.