Feline Health
Caring for Cats
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A Winn Feline Foundation Report On ...
Feline Infectious Peritonitis - UPDATES
Introduction by Janet Wolf
Over the past decade, The Winn Feline Foundation has taken a leadership
role in investigating the causes, prevention, and treatment of feline
infectious peritonitis. Early studies, conducted by Niels Pedersen and the
staff at the University of California at Davis, focused on
characterization of the disease. When the FIP vaccine was introduced, the
Foundation helped fund a scientific evaluation of the vaccine by Dr. Fred
Scott at Cornell University.
In 1994, Winn co-sponsored the First
International FECV/FIP Conference in cooperation with the Center for
Companion Animal Health at the University of California, Davis. Here, for
the first time, breeders and practicing veterinarians had an opportunity
to interact with the scientists and research veterinarians who were
investigating these challenging coronaviruses. The researchers shared
their findings, helping to increase the general body of knowledge about
FIP. Work groups of breeders, practitioners and scientists conferred and
came up with recommendations for catteries to reduce the incidence of FIP.
These recommendations have helped many catteries improve conditions and
limit the incidence of FIP.
Subsequently, the Winn Foundation has funded a
series of studies by Drs. Diane Addie and Oswald Jarrett at the University
of Glasgow, Scotland in which they have worked with breeders and other
owners of multi-cat households in Great Britain to better understand the
mode of transmission and how to raise coronavirus-negative litters. Other
studies have included work in Switzerland by Hans Lutz and Daniella Fehr
as well as studies which helped develop the polymerase chain reaction or
PCR test for the detection of FIP.
A research team led by Dr. Niels
Pedersen with the assistance of Dr. Janet Foley at the University of
California, Davis (UCD) has undertaken a number of studies which have also
increased our body of knowledge about FIP. Their first studies followed
cats in eight catteries in an effort to characterize the disease outside
the research environment. The Davis studies have added to our
understanding of the disease in cattery situations, the role of
inheritance, the effectiveness of some cattery management strategies and
possible preventive strategies. While there is still much to learn, each
new study gives us insights and information. At the end of this
introduction is a partial list of the articles on FIP that have resulted
from Winn funded research.
With this article, we begin a series of
progress reports on Winn-funded FIP research and updates on new testing
procedures. John August, MRCVS from Texas A&M University's College of
Veterinary Medicine will be reporting on the new tests being commercially
marketed for FIP detection. Other progress reports include an article
submitted by Diane Addie, who has advocated isolation and early weaning
strategies to reduce the incidence of feline infectious peritonitis in
multi-cat situations such as catteries. The second progress report is by
Janet Foley at UCDavis. It also explores the incidence of coronavirus in
multi-cat environments and specifically assesses early weaning as a
practical alternative in American catteries.
For further information:
- Report from the International FIP/FECV Workshop, University of
California, Davis, August 12-14, 1994, Feline Practice, Vol. 23, No. 3,
May/June 1995. (Copies are available from The Winn Feline Foundation for a
donation of $10.00; in Spanish $15.00.)
- "Risk Factors for Feline Infectious Peritonitis
Among Cats in Multiple-cat Environments with Endemic Feline Enteric
Coronavirus," by Janet E. Foley, DVM, MS, Amy Poland, Jeff Carlson, Niels
Pedersen, DVM, PhD, JAVMA, Vol. 210, No 9, May 1, 1997.
- "Patterns of Feline Coronavirus Infection and Fecal Shedding from Cats in Multiple-cat
Environments," by Janet E. Foley, DVM, MS, Amy Poland, Jeff Carlson, Niels
Pedersen, DVM, PhD, JAVMA, Vol. 210, No 9, May 1, 1997.
- "The Inheritance
of Susceptibility to Feline Infectious Peritonitis in Purebred Catteries,"
by Janet E. Foley, DVM, MS and Niels Pedersen, DVM, PhD, Feline Practice,
Vol. 24, No.1, January/February 1996.
- "Evaluation of the Safety and
Efficacy of Primucell-FIP Vaccine," F.W. Scott, DVM, PhD, W.V. Corapi,
DVM, PhD, C.W. Olsen, DVM, PhD, Perspectives on Cats, Fall 1992.
by John August, MRCVS
Texas A&M University's College of Veterinary Medicine
The accurate diagnosis of
feline infectious peritonitis (FIP) remains a challenge for practicing
veterinarians. Similarly, cat breeders remain frustrated about their
inability to identify cats that have been exposed to, and which may be
carriers of, pathogenic feline coronaviruses. Presently available
immunofluorescent antibody (IFA) tests are non-specific, failing to
differentiate between exposure to feline enteric coronavirus (FECV),
feline infectious peritonitis virus (FIPV), or coronaviruses from other
species.
In the February 1998 edition of their newsletter, Antech
Diagnostics describes a new test, the FIP-Specific ELISA, that has been
introduced by their laboratories recently. According to Antech, the test
is based on the fact that all pathogenic strains of FIPV have an intact 7B
region in their genetic code; this region is absent or truncated in many
strains of FECV and is not present in the virus included in the commercial
vaccine. Demonstration in cats of specific antibodies to the 7B protein,
produced by the 7B region, might suggest that the animals have been
exposed to a pathogenic FIPV, and may be carriers of the virus or
susceptible to disease.
Antech evaluated their new test in a group of 42
cats, including animals exposed to FIPV or FECV, or the FIP vaccine. Also
included were cats with proven clinical FIP, specific pathogen-free cats,
and cats from two catteries. According to Antech, only the FIPV-infected
cats had positive titers with the FIP-Specific ELISA test. Additionally,
there was an association in the catteries studied between positive titers
(>1:80) and the tendency to develop clinical FIP within three months. From
their preliminary data, Antech proposed that cats with titers of 1:160 or
greater on their new test are infected with FIPV. Also, cats with titers
of 1:320 or greater have a 50% likelihood of dying from the disease within
three months. Clearly, Antech's early claims concerning this new test are
very intriguing to veterinarians and breeders; however, as with all new
tests, the results should be interpreted cautiously until the test has
undergone widespread validation on a large number of cats in the general
population.
Complicating the interpretation of these new test results is
the ongoing concern by some research groups that pathogenic feline
coronaviruses (FIPV) cannot be differentiated reliably from their
non-pathogenic counterparts through differences in the 7B region of the
coronavirus genome. In 1995, Herrewegh and colleagues reported in the
journal Virology that deletions in the 7A/7B region did not occur in all
FECV isolates. In 1998, Kennedy and colleagues reported in the Journal of
Veterinary Diagnostic Investigation that their polymerase chain reaction
test was unable to consistently differentiate FECVs and FIPVs when applied
to the 7A/7B region. Veterinarians and breeders interested in the control
of FIP are encouraged to follow the literature closely to determine how
these discrepancies will affect the accuracy of commercial tests being
offered for the detection of FIPV.
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Please Note: The Winn Feline Foundation provides the feline health
information on this site as a service to the public. Diagnosis and
treatment of specific conditions should always be in consultation with
one's own veterinarian. The Winn Feline Foundation disclaims
all warranties and liability related to the veterinary advice and
information provided on this site.
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