Feline infectious peritonitis (FIP) is the leading infectious cause of cat death. FIP occurs when there is an excessivly inflammatory immune response to feline coronavirus (FCoV) infection. Most cats simply become infected, shed FCoV for a a few months, mount an immune response, eliminate the virus and live happily ever after (see How to eliminate FCoV infection from a cattery or household of cats). However, for reasons that we don't yet fully understand, instead of clearing FCoV infection, an unfortunate few cats develop FIP.
The name FIP is slightly misleading: FIP isn't inflammation of the peritoneum (the lining of the abdomen) it is a vasculitis (inflammation of the blood vessels). The clinical signs which the cat develops depend on which blood vessels are damaged, and on which organ(s) the damaged blood vessels supplied.
The key event in the development of FIP is the infection of the monocyte (a white blood cell) by feline coronavirus (FCoV). From the moment of infection of the monocyte, the cat’s fate hangs on whether or not that monocyte can contain the virus and eventually defeat it, or whether the virus wins, and begins replicating within the monocyte [Dewerchin et al, 2005]. In the animation shown below, we depict the latter. We show how the virus hijacks the immune system, leading to an inflammatory sequence of events which results in a pyogranuloma forming around a blood vessel. In the film we show the development of acute FIP, where there is a lot of virus, many blood vessels affected, and the resulting leakage from damaged blood vessels causes the clinical signs of effusive FIP – ascites, thoracic effusion, pericardial effusion.
In non-effusive FIP the course is more chronic: fewer blood vessels are affected, the cat’s immune system tries harder to contain the infection, leading to larger pyogranulomata and the clinical signs of chronic inflammation and relating to the organ(s) containing the pyogranulomas.
I am very grateful to Dr Francois Bagaini, of vetocyte.fr for making this animation for me:
Wet
or effusive FIP
This is the acute form of the disease, where many blood vessels
are damaged severely and fluid leaks out of them into the abdomen
or the thoracic (chest) cavity. When the blood vessels in the abdomen
are affected, the cat's tummy swells up with fluid called ascites.
When the blood vessels in the thorax are damaged fluid leaks into the chest, impairing the ability of the lungs to expand and the cat shows difficulty breathing. Dr Greg Martinez made a good YouTube film to show this:
The thoracic form of wet FIP is less acute than the abdominal form, and some cats with thoracic FIP can survive many weeks or months.
Dry or non-effusive
FIP
Dry FIP
is the more chronic form of the disease. In dry FIP, the cat often
has vague clinical signs, such as going off his or her food, losing
weight, the coat looking dull. Many cats with dry FIP become jaundiced
(icteric), when you look inside the eyelid, it looks yellow. If
the cat has a pale nose, you may notice that that looks yellow.
Many cats with dry FIP get signs in their eyes: usually the iris
(the coloured part of the eye around the pupil) changes colour,
parts of it may appear brown (see photos).
(Many thanks to Mrs M. for this photograph.)
The cat may bleed into the eye, or white precipitates appear on the cornea (the clear membrane on the front of the eye). For vets: check the eyes using an ophthalmoscope for vitreous flare and retinal vessel cuffing (see photo below).
(Many thanks to John Mould for this photograph.)
Around 12% of cats with non-effusive
FIP develop neurological signs: often they become ataxic (wobbly
and falling over when walking), they may have head tremors, fits,
their eyes may dart from side to side instead of being focussed.
However, all of these clinical
signs can be caused by other, sometimes treatable, conditions, which
is why accurate diagnosis is essential.
Diagnosis of FIP –
this section is intended for veterinary surgeons
FIP is a notoriously
difficult condition to diagnose, many other conditions present with
very similar clinical signs. Definitive diagnosis is only possible
at post mortem, or occasionally by biopsy (though for accurate biopsy
results one has to actually biopsy a visible pyogranulomatous lesion,
which may necessitate laparotomy). Only 18% of samples sent to our
laboratory for FIP diagnosis turn out to be FIP. Since cats with
FIP are usually euthanased, it is absolutely vital that FIP is accurately
differentiated from other, treatable, conditions.No matter what any laboratory or manufacturer of test kits claims, there is no single test for FIP – diagnosis is a challenge to even the most competent veterinary clinician and involves following a series of steps on an algorithm (download catvirus.com FIP flowchart). [The European Advisory Board of Cat Disease (ABCD) FIP algorithm was based on this flowchart (Addie et al, JFMS, 2009).] Diagnosing FIP
consists of a number of steps as shown in the flowchart. Until you have a lot of experience in diagnosing FIP, you might find it useful to use the chart, and also the catvirus.com FIP diagnosis worksheet.
Download catvirus.com FIP flowchart
Download catvirus.com FIP diagnosis worksheet.
The rest of this section will take you step by step through the FIP diagnosis flowchart:
Step 1: The cat's history is consistent with a diagnosis of FIP
Step 2: Clinical examination suggests either effusive or non-effusive FIP as a possible diagnosis
Step 3: Effusive (“wet”) FIP - analysis of the effusion
Step 3: Non-effusive (“dry”) FIP blood sample
Step 4: Analysis of an effusion by a specialist laboratory
Step 4: Non-effusive ("dry") FIP - analysis by a specialist laboratoryExample of using the catvirus.com FIP diagnostic algorithm:
Case history - Does Pancho have Non-effusive FIP?
To submit a sample to the University
of Glasgow for a FIP profile
Feline coronavirus antibody tests
Virus
detection by RT-PCR
Step 1: The cat's history is consistent with a diagnosis of FIP
There are usually 2 key aspects in the cat's history which suggest that FIP is a possible diagnosis of his or her presenting signs: first the cat MUST have become infected with feline coronavirus (FCoV) in order to have developed FIP, therefore there will be a history of having been in a multicat environment, such as at a cat breeder's, or a rescue shelter, within the previous 18 months. (Development of FIP more than 18 months after infection would be very unusual, though does occur in geriatric cats or immunosuppressed cats, e.g. cats undergoing chemotherapy, or cyclosporine A (Atopica, Novartis) treatment, or after becoming infected with feline leukaemia virus or feline immunodeficiency virus. A cat living indoors alone all his or her life will be very unlikely to have developed FIP (though check for a history of having stayed in a boarding cattery, or some other opportunity for exposure – e.g. recent adoption of a kitten). M ost cats with FIP have a history of having had a stress of some sort – being neutered, rehomed, the introduction of a new kitten, even something as simple as a booster vaccine (Addie et al, 2020)etc. Incubation for effusive FIP is usually a few days up to one month. The incubation period for non-effusive FIP can be up to a year. FIP is most common on first exposure to the virus - if a cat has been infected with FCoV for over a year, it is unlikely he or she will develop FIP.
Step 2: Effusive (“wet”) FIP - clinical signs
Effusive FIP is the more acute condition – occurring within 4-6 weeks of a stressful event in the cat’s life, whereas non-effusive FIP can incubate for months to years. If you understand that FIP is an immune-mediated vasculitis it becomes easier to understand how it is able to manifest with so many varied clinical signs. Any blood vessel to any organ can be affected and the clinical signs will result from damage to that organ. In effusive FIP, many blood vessels are affected, allowing fluid to leak out into the abdomen, thorax or pericardium. Thus the cat presents with ascites or pleural or pericardial effusion. The ascitic cat may appear to have put on weight, although ribs are usually more palpable. The Orion Foundation call FIP “the purring disease” because the cat may still be bright and eating, though some are dull and anorexic. The temperature of cats with FIP rarely exceeds 103oF (39oC). A cat with a pleural effusion will present with dyspnoea.
Step 3: Effusive (“wet”) FIP - analysis of effusion
Total protein in the effusion and albumin:globulin ratio (A:G)
FCoV antibody test in the effusion
Alpha one acid glycoprotein (AGP)
Rivalta testTo perform a Rivalta test, take 10 mls of water (must be at room temperature), add 2-3 drops of 8% acetic acid (ordinary clear/white vinegar) and carefully layer a drop of the effusion into it. If the effusion dissipates like a wisp of smoke in air the Rivalta test is negative and the cat is 97% not likely to have FIP. If, however, the effusion hangs from the surface in a globule, then slowly floats down like a jellyfish, the Rivalta test is positive. A positive Rivalta test means that the cat is 86% likely to have FIP (i.e. 5 of 6 cats with a positive Rivalta test do have FIP, so clearly other tests need to be performed to be more certain of the diagnosis).Watch a film of the Rivalta test:
Reference:
Total protein in the effusion
and albumin:globulin ratio (A:G)
The total protein concentration in the effusion of a cat with FIP is usually greater than 35 g/l and this usually consists of more globulin than albumin, pushing down the albumin to globulin (A:G) ratio. To calculate the A:G ratio, divide the albumin by the globulin values. An A:G of < 0.4 indicates FIP is quite likely; an A:G of >0.8 rules out FIP; A:G of between 0.4-0.8 is inconclusive - consider other parameters. The A:G of an effusion is one of the most useful tests to perform in practice for a quick indicator of whether or not a cat may have FIP and can be easily performed on an in-house biochemistry analyser machine.
Cytology
In effusive FIP, there are generally
less than 3 x 10 9 nucleated cells per litre in the effusion and
the cells are predominantly neutrophils and macrophages (see photograph below). In bacterial
peritonitis and pleurisy, the white blood cell count in the effusion
is much higher and the cytologist will usually see bacteria (if
they are intracellular, this indicates that they were not simply
contamination of the sample). Cytology of pleural effusions is useful
for differentiation of thymic lymphosarcomas, since the predominant
cell is the lymphocyte and they often appear malignant.
.
FCoV antibody titre
The presence of antibodies indicates
that the cat has been infected with FCoV, the cause of FIP. Any
FCoV antibody titre can occur in cases of wet or effusive FIP, but
most cats with FIP have extremely high antibody titres (1280 or
greater). Antibody titres of 0 are unusual in FIP cases and are
usually considered as indicating that the cat does not have FIP.
(However, if other parameters suggest a diagnosis of FIP,
despite having an antibody titre of 0, then this is the one situation
where FCoV RNA detection (RT-PCR), performed on a sample of the
effusion, is diagnostic of FIP. In these cats there is so
much virus in the effusion that all the antibody is bound to it,
and none is available to bind to virus in the test.)Note:
many healthy cats and cats with diseases other than FIP have FCoV
antibodies. The presence of FCoV antibodies alone is NOT diagnostic
of FIP, if the other parameters of the profile do not indicate a
diagnosis of FIP.To read about FCoV antibody tests in far greater detail, visit www.catvirus.com/FCoVantibody.htm
Step 4: Effusive (“wet”) FIP - analysis of effusion by a specialist laboratory
Alpha one acid glycoprotein (AGP)
Virus detection in macrophages (IF) positive
Virus RNA detected by RT-PCR in the effusionAGP level
Alpha one
acid glycoprotein (AGP) is an acute phase protein which has been
shown to be very useful in distinguishing FIP from other clinically
similar conditions. In FIP, AGP levels are usually greater than
1500 micrograms/ml. In normal cats, it’s up to 500 micrograms/ml (i.e. 500 mg/l). In cats with bacterial
peritonitis or pleurisy the AGP is also raised, which is why cytology
is also necessary to differentiate these conditions. In cardiomyopathy,
non-infectious liver disease and tumours, which are the most common
conditions mistaken for FIP, AGP is normal.In the USA, AGP testing kits
can be obtained from Cardiotech
Services. Enquiries
to Jeff Sarno or call (502)473-7066.
Virus detection in macrophages by direct immunofluorescence or immunohistochemistry
Detection of FCoV in macrophages in an effusion by direct immunofluorescence is diagnostic of FIP, but a negative result is more difficult to interpret (Hartmann et al, 2003). This test is not currently widely available.
Viral RNA detected by RT-PCR in the effusion
Reverse transcriptase polymerase chain reaction (RT-PCR) detects the RNA of the FCoV – i.e. is a test which detects actual virus. Quantitative RT-PCR (RT-qPCR) is an interesting recent development in which the amount of virus in the sample may be measured. RT-PCR is useful in control of FCoV infection in households of healthy cats and is useful in FIP diagnosis on organs of cats in biopsy or post mortem specimens.
Detection of FCoV RNA in the blood or faeces is not diagnostic of FIP, since some healthy FCoV antibody positive cats, or animals with non-FIP illness, are also positive. In addition, cats with FIP may be negative – the effusion of cats with FIP is often negative.
Summary
A cat with
wet FIP should be FCoV seropositive, the total protein of the effusion
must be over 35g/l and the albumin:globulin less than 0.4 (or at
least less than 0.8), the AGP should be high (over 1500 micrograms/ml)
and the cytology should reveal few nucleated cells which are mainly
neutrophils and macrophages. A Rivalta test should be positive. Diagnosis can be confirmed by detecting FCoV in the macrophages in the effusion.
Step 2: Non-effusive (“dry”) FIP - clinical signs
If you understand that FIP is an immune-mediated vasculitis it becomes easier to understand how it is able to manifest with so many varied clinical signs. Any blood vessel to any organ can be affected and the clinical signs will result from damage to that organ. FIP is generally defined as either “wet” (effusive) or “dry” (non-effusive) but neither is clear cut and an effusive case can become non-effusive or vice versa. Effusive FIP is the more acute condition – occurring within 4-6 weeks of a stressful event in the cat’s life, whereas non-effusive FIP can incubate for months to years. In the longer incubating non-effusive, FIP, fewer blood vessels are affected than in effusive FIP and the immune response is more chronic, leading to larger pyogranulomata. The cat loses weight gradually, is chronically pyrexic, and becomes dull and anorexic. Most cats with dry FIP have palpably enlarged mesenteric lymph nodes and intraocular lesions. Clinical signs will depend on which organs are involved:
- if the liver is affected, the cat will be jaundiced (icteric) if the meninges/hydrocephalus are affected, neurological signs (ataxia, nystagmus, fits, loss of reflexes) will occur
- if the eyes are affected there will be uveitis, aqueous flare, vitreous flare, retinal vessel cuffing, corneal precipitates, haemorrhage into anterior or posterior chambers (see photographs above on this page)
Step 3: Non-effusive (“dry”) FIP blood sample
Haematology - reveals a non-regenerative anaemia and lymphopenia
Hypergammaglobulinaemia causing low albumin:globulin (A:G) ratio
Alpha 1 acid glycoprotein (AGP) in non-effusive FIP diagnosis
Haematology reveals a non-regenerative anaemia and lymphopenia
In non-effusive
FIP there is lymphopenia, a mild non-regenerative anaemia with a haematocrit
of 30% or less and often a neutrophilia with a shift to the left.
Bear in mind that cats with other chronic infections can have similar
haematological changes. Haematology is useful in differentiating
FIP from Haemobartonella
felis infection where
the anaemia is regenerative and there may be organisms visible on
the erythrocytes.
Hypergammaglobulinaemia causing low Albumin:Globulin ratio
(A:G) ratio
In FIP
the globulin concentration in serum or plasma is raised to over
40g/l. Consequently the A:G is usually lowered. An A:G of < 0.4
indicates FIP is quite likely, provided that globulins are raised,
remember than a low albumin (e.g. in liver disease) can also artificially
lower the A:G. An A:G of >0.8 rules out FIP; A:G of between 0.4-0.8
- consider other parameters.In addition, often bilirubin levels are raised, although other liver enzymes may be normal.
FCoV antibody titre
FCoV antibody titres in dry
FIP are usually extremely high. An antibody titre
of zero rules out non-effusive FIP.Note:
many healthy cats and cats with diseases other than FIP have FCoV
antibodies. The presence of FCoV antibodies alone is NOT diagnostic
of FIP, if the other parameters of the profile do not indicate a
diagnosis of FIP. A healthy cat with a high FCoV antibody titre
is NOT a cat with dry FIP.To read about FCoV antibody tests in far greater detail, visit www.catvirus.com/FCoVantibody.htm
AGP level
AGP is an acute phase protein
which is useful in distinguishing FIP from other clinically similar
conditions. In FIP, AGP levels are usually greater than 1500 ug/ml.
In normal cats, it’s up to 500 ug/ml. Bear in mind, however, that
AGP is not specific, and will also be raised if there is viral (non-FIP),
bacterial (e.g. ascending cholangiohepatitis or pyelonephritis)
or fungal infections or recent trauma. AGP measurement is useful
in distinguishing FIP from neoplasia or non-infectious liver disease,
when AGP levels will be normal. In the USA, AGP testing kits
can be obtained from Cardiotech
Services. Enquiries
to Jeff Sarno Onras43@aol.com or call (502)473-7066.
Step 4: Non-effusive (“dry”) FIP - analysis by a specialist laboratory Alpha one acid glycoprotein (AGP)Virus RNA detected by RT-PCR in the effusion
AGP level
Alpha one
acid glycoprotein (AGP) is an acute phase protein which has been
shown to be very useful in distinguishing FIP from other clinically
similar conditions. In FIP, AGP levels are usually greater than 1500 ug/ml.
In normal cats, it’s up to 500 ug/ml. Bear in mind, however, that
AGP is not specific, and will also be raised if there is viral (non-FIP),
bacterial (e.g. ascending cholangiohepatitis or pyelonephritis)
or fungal infections or recent trauma. AGP measurement is useful
in distinguishing FIP from neoplasia or non-infectious liver disease,
when AGP levels will be normal. In the USA, AGP testing kits
can be obtained from Cardiotech
Services. Enquiries
to Jeff Sarno or call (502)473-7066.
Reverse transcriptase polymerase chain reaction (RT-PCR) detects the RNA of the FCoV – i.e. is a test which detects actual virus. Quantitative RT-PCR (RT-qPCR) is an interesting recent development in which the amount of virus in the sample may be measured. RT-PCR is useful in control of FCoV infection in households of healthy cats and is useful in FIP diagnosis on organs of cats in biopsy or post mortem specimens.
Detection of FCoV RNA in the blood or faeces is not diagnostic of FIP, since some healthy FCoV antibody positive cats, or animals with non-FIP illness, are also positive. In addition, cats with FIP may be negative – the blood of cats with FIP is usually negative. In non-effusive FIP, detection of large amounts of virus in a fine needle aspirate of a mesenteric lymph node is highly indicative of FIP. However, detecting FCoV in the CSF of cats is not diagnostic – healthy cats and cats with non-FIP conditions are occasionally positive (detecting FCoV antibody in the CSF is more useful).
Summary
A cat with dry FIP should have
a high FCoV antibody titre, be hyperglobulinaemic and have a reduced
albumin:globulin ratio. He or she should have a high AGP, lymphopenia,
a haematocrit of less than 30% which is non-regenerative and possibly
a neutrophilia. Clinically, the cat should have lost weight and
will usually have ocular signs such as iritis, retinal vessel cuffing,
keratic precipitates, aqueous or vitreous flare.Remember:
a healthy cat with a FCoV antibody titre is NOT a cat with dry FIP.
For Step 5 of the algorithm - treatment - go to www.catvirus.com/treatment.htm
Example of using the catvirus.com FIP diagnostic algorithm: Case history Does Pancho have Non-effusive (“dry”) FIP?
(Note to veterinary surgeons - this video counts for 15 minutes continuing professional development.)
Recommended veterinary surgeons with specialist FIP and FCoV knowledge
This list is very much in its infancy and so far the majority of recommended FIP specialist veterinarians are in the UK.
Japan
Dr Yasuda Hidemi BVSc.
AlphaVets Co.Ltd
Yasuda Veterinary Clinic
1-5-22 Midorigaoka Meguro-ku
Tokyo 152-0034
http://yasuda-vet.org/clinic.html
You Me Animal Clinic, Sakura-shi, Japan.
Dr Katayama, Bloom Animal Hospital, Kajiyama 1-10-32, Tsurumi, Yokohama City 230-0072, Japan.
UK
Dr Charlotte Aston: has experience treating effusive FIP and FCoV shedding monitoring. Charlotte impresses me with the way she cares intensely about her patients.
Melton Vets
6 North Street,
Melton Mowbray,
Leicestershire,
LE13 1NL,
England
Tel. No. 01664 560364
Website: https://melton-vets.co.uk
Dr Mark Fosbery, BVMS BSc (Hons) MRCVS
Dr Fosbery is co-author with me in several papers: he is a veterinary surgeon of exceptional knowledge and caring. He has experience of treating cats with FCoV and FIP.
Newnham Court Veterinary Hospital
CVS House,
Owen Road,
Diss,
Norfolk
IP22 4ER
Website: www.newnhamvets.co.uk
Dr John Mould, BA, BVSc, DVOphthal, FHEA, MRCVS: veterinary ophthalmologist. It was John who taught me about the intra-ocular signs of FIP and many of the eye photos I use on the website and in my lectures come from him. John is compassionate, thorough, knowledgeable.
Veterinary surgeons: if you need pathology on an eye, send it to the Eye Veterinary Clinic and get advice about how to preserve it first: don't stick the eye in formalin.
Eye Veterinary Clinic Ltd.,
Marlbrook
Leominster
Herefordshire
HR6 OPH
England
Email: info@eyevetclinic.co.uk
Tel.No: 01568 616616
Fax: 01568 615884
Website: www.eyevetclinic.com
Dr Jacques Penderis, BVSc MVM PhD CVR DipECVN MRCVS: neurology consultant with enormous FIP experience and expertise.
http://vet-neurology.co.uk/
Broadleys Veterinary Hospital
Craigleith Road,
STIRLING FK7 7LE
Scotland
Tel: 01786 445 665
Website: http://www.broadleysvets.co.uk/specialist-care/neurology
Dunblane Clinic | Tel: 01786 824 400
1a Station Road, DUNBLANE FK15 9ET
Sherwood Vets in Ashford and Hampton, England.
I am super impressed with Max King and Toby Hartshorn from this practice: not just their skill, but how exceptionally caring they are.
Website: https://www.sherwoodvets.co.uk
Dr Elise Robertson BS BVetMed MACVSc (Feline) DipABVP (Feline) MRCVS
American Board Certified Diplomate Feline Practice
Elise is an expert in endoscopy; she has a large experience of treating non-effusive FIP with both Virbagen Omega and Polyprenyl Immunostimulant. Based in England.
Feline Vet Referrals www.felinevet.net
email: e.robertson[at]felinevet.net
Endoscopy Vet Referrals www.endoscopyvet.net
email: e.robertson[at]endoscopyvet.net
Phone: 01273 931 139
efax: 01273 376 932
USA
Jerry Murray DVM Jerry is an expert in felne and ferret coronavirus and infectious peritonitis.
Animal Clinic of Farmers Branch
14021 Denton Drive
Dallas,
TX 75234
USA
Tel no: 972-247-2221
Email: AFERRETVET@cs.com
Recommended laboratories for FCoV and FIP tests
I'm sorry that I do not yet have recommendations for laboratories in all countries.
Japan
Russia
Veterinary Pathology Diagnostic Services
University of Sydney George Tsoukalas
Laboratory Manager
Phone: +61 2 9351 3099
Fax: +61 2 9351 7421
Email: G.Tsoukalas@usyd.edu.auAustralian FCoV/FIP expert: Dr Jacqueline Norris BVSc, MVSt, PhD, Grad Cert Ed Stud (Higher), IVAS Cert Acup.
Senior Lecturer in Veterinary Microbiology
Faculty of Veterinary Science
University of Sydney 2006
Australia
www.vetsci.usyd.edu.au
RT-qPCR to test for feline coronavirus:Scanelis laboratory.
IFA using TGEV:Contact: Dr Sophie de Poder UMR 1161-Virologie, Ecole Nationale Vétérinaire d'Alfort, 7 avenue du Général de Gaulle,94704 Maisons-Alfort, France.Dr Addie's laboratory: Feline Institute PyreneesMaison Zabal64470 EtchebarFranceSend as much sample as you can (leftover samples are used in research). FCoV antibody
tests:Dr Joel GodenirLABORATOIRE
VETERINAIRE DEPARTEMENTAL
105, route des Chappes,
BP 107,
06902 SOPHIA ANTIPOLIS Cedex,
FRANCE
Téléphone:
04 92 96 00 00
Fax: 04 92 96 01 20 Cost: 21 euros HT, (25.12
euros tax included)This laboratory declined to take part in the assessment, however I paid to have a few tests examined - there were some false positive results given.
Italy boasts more than its share of FCoV experts: AGP testing and immunofluorescence of macrophages in effusion - Prof. Saverio Paltrinieri is the world expert in feline alpha 1-acid glycoprotein (AGP) and he and his colleague developed the technique of direct fluorescence in macrophages in effusionsFCoV RT-PCR - Dr Nicola Decaro (this young man is the world expert in canine coronavirus!) FCoV antibody testing - Dr A. Pratelli (email: a.pratelli@veterinaria.uniba.it)
Prof. Saverio Paltrinieri's laboratory: Dipartimento di Patologia Animale Igiene e Sanità Pubblica VeterinariaUniversity of MilanVia Celoria 1020133 MilanoItaly Drs Decaro and Pratelli are based at the University of Bari. The University of Bari laboratory uses their own quantitative RT-PCR for detection of coronavirus. They developed their own antibody ELISA cited in Pratelli et al, 2008 and Pratelli et al, 2009 and has the technology to do immunofluorescence, virus neutralisation testing and western blotting. They are also able to differentiate IgA and IgG. I highly recommend this laboratory.Department of Public Health and Animal Sciences, Faculty of Veterinary Medicine, University of Bari, Italy.
Switzerland This is the laboratory of world renowned FCoV/FIP expert Prof. Hans Lutz and is run by another expert and highly efficient scientist: Dr Marina Meli. It was in this laboratory that the first RT-qPCR to detect FCoV was developed. They also offer a TGEV indirect immunofluorescent antibody test. Zurich Veterinary School
Clinical Laboratory, University of Zurich,Winterthurerstr. 260, CH-8057, Zürich,
SwitzerlandPhone +41 44 635 81 11Fax +41 44 635 89 06
To submit
a sample to the University of Glasgow for FCoV antibody testing or FIP profile
Note
that the FIP profile is NOT for use in healthy cats. To screen a
healthy cat for exposure to FCoV, simply send a heparin blood sample
for a FCoV antibody titre.
Effusive or wet FIP: send 1ml heparin blood and 1-2ml effusion in plain and EDTA tubes. (Note: sending the effusion will greatly increase the chances of an accurate diagnosis.)
Non-effusive or dry FIP: send 2 x 1ml heparin blood and 1 ml EDTA blood and two air-dried blood smears. Send samples with a test request form (can be downloaded from Veterinary Diagnostics Services or obtained by calling UK 0141 330 5777) or with a note of your address to:
Veterinary Diagnostics Services
University of Glasgow Veterinary School
Bearsden
Glasgow
G61 1QH
UK
Download a sample submission form here. (It will open in a new tab.)
Biobest have their own IFA (probably a type II FCoV) which works extremely well. Their FCoV antibody test was featured in three peer-reviewed publications and compared favourably in an independent study. Their contact is Dr Paul Burr.
Biobest Laboratories Ltd
6 Charles Darwin House
The Edinburgh Technopole
Milton Bridge
Nr Penicuik
EH26 0PYTel: +44 (0)131 440 2628
Fax: +44 (0)131 440 9587
Email: enquiry[at]biobest.co.uk
Pinmoore Laboratories are not recommended: they would not divulge which FCoV RT-PCR they use and seem to be unable to give virus quantity.
Lucy Whittier Molecular and Diagnostic Core Facility.
This is the veterinary diagnostic laboratory of the legendary Dr Niels Pedersen - the number 1 world expert on FIP! He is also the man who discovered Feline Immunodeficiency Virus! You can download a sample submission form from the website.
Lucy Whittier Molecular & Diagnostic Core Facility
School of Veterinary Medicine
Department of Medicine and Epidemiology
3110 Tupper Hall
University of California, Davis
Davis, CA 95616Phone: 1 530 752 7991
Fax: 1 530 754 6862
Cornell University College of Veterinary Medicine
Antech Laboratories are NOT recommended
AGP testing kits can be obtained
Feline coronavirus
antibody tests
This section has been moved to http://www.catvirus.com/FCoVantibody.htm.
Virus
detection by RT-PCR
See also What is RT-PCR. RT-PCR detects the FCoV genome,
so indicates presence of the viral RNA. RT-PCR testing has eclipsed biopsy for FIP diagnosis: a positive FCoV RT-PCR test on ascites, pleural or pericardial effusion or a fine needle aspirate from an organ is highly suggestive of FIP.
However, you cannot use RT-PCR results on faeces to diagnose FIP because cats with illnesses other than FIP can co-incidentally have coronavirus in their faeces.
In my research survey, I found that it was less useful to use RT-PCR than a sensitive FCoV antibody test: to show that a cat has eliminated FCoV required only one antibody titre of less than 10 in our laboratory, but required 5 monthly negative RT-PCR tests on faeces. However, RT-PCR remains the only way to detect a carrier cat - a cat who sheds FCoV continually for 9 months or more is likely to be a lifelong carrier.
At time of writing, there is no RT-PCR which can differentiate FIP-causing coronaviruses from coronaviruses which do not cause FIP. My belief is that all feline coronaviruses are capable of causing FIP, if the cat is exposed to a high enough dose or if the cat is immunosuppressed, for example by long-term corticosteroid use, or concurrent feline leukaemia virus infection.
Treatment of FIP –
this section is intended for veterinary surgeons
What clinical signs (symptoms) should I look out for in my cat?
Any of the following clinical signs should alert you to the possibility of your cat developing FIP:
weight loss
recurring fevers (usually detected when
your veterinary surgeon takes the cat's temperature)
going off food
the cat becomes even lazier
than usual
sudden swelling of the abdomen
look closely at your cat's eyes regularly,
watch for any change in colour of the iris (the coloured area of
the cat's eye around the pupil) or any cloudiness, or bleeding (look
closely at the cats' eyes in the Dry or non-effusive FIP section to get an idea of what you are looking
for)
difficulty breathing (the cat breathing through his or her mouth)
if the cat
has a fit or seizure
if the cat seems to lose balance, become clumsy
if the cat's
personality changesIf you are a cat breeder,
the following signs in your kittens should alert you to the possibility
of FCoV being present in your cats:
kittens of uneven size in a litter
diarrhoea
in kittens around 5-7 weeks of age
transient sneezing or discharge from the
eyes in young kittensRemember that all of the
clinical signs described above can occur due to other, curable,
conditions, so take your cats to your veterinary surgeon to be checked
if any of these signs occur and hope for the best. Remember that
8 out of 10 cats whose samples were sent to our laboratory for FIP
diagnosis turned out not to have FIP at all!
Addie D.D., Jarrett O. 1992. A study of naturally occurring feline coronavirus infection in kittens. Vet. Rec. 130: 133-137.
Addie D.D., Jarrett O. 1992. Feline coronavirus antibodies in cats. Vet. Rec. 131: 202-203.
Addie D.D., Toth S. 1993 Feline coronavirus is not a major cause of neonatal kitten mortality. Feline Practice 21: (5) 13-18.
Addie DD, McDonald M, Audhuy S, Burr P, Hollins J, Kovacic R, Lutz H, Luxton Z, Mazar S, Meli M. 2012 Quarantine protects Falkland Islands (Malvinas) Cats from Feline Coronavirus Infection. J Feline Med Surg. 14 2 171-176.
Addie DD, le Poder S, Burr P, Decaro N, Graham E, Hofmann-Lehmann R, Jarrett O, McDonald M, Meli ML. 2015. Utility of feline coronavirus antibody tests. J Feline Med Surg. 17(2):152-62.
Meli ML, Burr P, Decaro N, Graham E, Jarrett O, Lutz H, McDonald M, Addie DD. 2013. Samples with high virus loads cause a trend toward lower signal in feline coronavirus antibody tests. J Feline Med Surg. 15: (4) 295 – 299.
paragliding
last updated 5 April 2023
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