FIP and pedigree cats

Re: FIP and pedigree cats

Alex Allen — Wed, 08 Dec 2010 15:34:07 GMT

Virbac has both a vaccine (Canileish - to be launched commercially next year) and treatment (Milteforan) for leishmaniasis - just not in UK.... Milteforan is available via SIC though - We started to stock it here in the UK due to the worryingly increasing number of cases now residing in UK.

My fault as well for not being clear... treatment doesn't necessarily mean cure but more often control or attenuation of the clinical signs - as in several vaccinations.

Re: FIP and pedigree cats

Martin Atkinson — Wed, 08 Dec 2010 15:08:16 GMT

[quote user="Alex Allen"]

On the positive side several diseases that previously puzzled us with their immune mediated pathologies have now been successfully treated/ vaccinated against - examples include malaria, leishmaniasis, felv - so there is hope.....

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Since when has there been a commercially available & reliable vaccine against malaria (or leishmaniasis for that matter)? And I'm not aware of anything that 'successfully' treats either, only merely controls - rather unreliably.

Re: FIP and pedigree cats

Alex Allen — Wed, 08 Dec 2010 13:10:29 GMT

[quote user="Martin Atkinson"]

From my experience FCoV antibody titres are not related to the likelihood of an individual cat developing FIP.

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Absolutely, personally I've seen low titres that have had wet FIP and it's been noted elsewhere as well. This is the trouble with the disease - we know a lot but not enough! A simple explanation for this is that the cat has either not had time to produce sufficient antibodies to FECoV or the circulating antibodies are bound due to excessive antigen.

In relation to the vaccination and diarrhoea I doubt this will make a blind bit of difference as recovered healthy cats can remain asymptomatically infected continually shedding the FECoV. Certainly whilst the kitten is not 100% healthy it should not be vaccinated - as per datasheet recommendations.

My crude theory has been based on the laws of probability - if there is FECoV +++ in a colony then the odds of the critical mutation occuring in vivo increase but that alone won't predict the incidence of FIP developing. The genetics / external factors such as stress must come into play when the cat's immune system is handling the FIPV. Having a narrow gene pool such as a pedigree cat colony is potentially going to increase the risk of that mutant virus causing clinical FIP.....probably . FIPV aims for monocytes (Monocyte is broad term for a whole family of cells with varying roles) using a common receptor found on these cells so invasion of these cells is going to occur irrespective of the genes but it's the next stages of the immune response that hold the key.

Is it more common in young animals due to their innate immune system not being dominated by an "experienced" immune system or is it the lack of adapted immunity that prevents the down regulation of the excessive cytokine release??? Studies have shown that the imbalance between Th1 and Th2 pathways have a significant influence on the outcome - low TNFalpha / high IFN gamma can be protective....but what makes a cat produce this balance over the disease causing excessive TNF alpha production??

Attempts to control the abnormal immune response that causes the vasculitis have repeatedly failed - TNFalpha inhibitors, IFNw, cyclophosphamide,corticosteroids etc have all been tried and tested with generally depressing results. Vaccination against FIP also has been unsuccessful or variable.

Re: FIP and pedigree cats

Mark Holmes — Wed, 08 Dec 2010 11:31:42 GMT

[quote user="Martin Atkinson"]

From my experience FCoV antibody titres are not related to the liklihood of an individual cat developing FIP. The major, and probably related, contributory factors are stress and population density so to go back to the OP, I would be advising obtaining a kitten from a responsible (long shot!) hobby breeder who has just a couple of cats in clean home environment. However I also believe that there is an immune-mediated/stress related link to vaccination to the extent that I will advise not vaccinating kittens with suspected FCoV diarrhoea (especially FeLV vaccine) until the diarrhoea has cleared up. This advise could be modified these days by the availability of PCR testing for FCoV virus in faeces. However as there is no current ability to differentiate potentially FIP causing strains of FCoV in commercial laboratories this is still limiting in the advice I feel I can give.

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Absolutely, I do wonder when jittens are in isolation from other cats and there is no rush to get them out for walks why there is such pressure to vaccinate early. Newly weaned,removed from litter mates then newly homed then taken to the vets then vaccinated. Stress, stress, stress, stress. I often suggest postponing the primary vaccination course, particularly if the source of the kittens is not ideal.

Re: FIP and pedigree cats

Martin Atkinson — Wed, 08 Dec 2010 11:03:05 GMT

Re: FIP and pedigree cats

Richard Fox — Tue, 07 Dec 2010 15:00:45 GMT

From a paper I found from 2006:

This study reinforces the complexity of interpreting serological tests for FCoV in both healthy cats and patients with signs compatible with FIP. Unique to this study is the detection of a significant relationship between breed and median FCoV antibody titre. This supports the theory that breed related differences exist in response to FCoV infection. The distribution of median Coronavirus antibody titres by breed was very similar to the pattern of breed predisposition to FIP recently reported in Sydney.

Re: FIP and pedigree cats

Kate Richardson — Tue, 07 Dec 2010 14:53:22 GMT

Or may be due an inherent breed related defect in their immune system, especially as they are related individuals? Birmans, in my experience, are a breed that figure strongly in my list of breeds I have seen with FIP. Plus breeder=multicat household=stress (in some cases)=risk factor.

Re: FIP and pedigree cats

Simon Neuhoff — Tue, 07 Dec 2010 14:27:45 GMT

One of our clients - a breeder - has now lost two cats to FIP and we are now treating two others for symptoms we suspect are due to FIP. Two other in contact cats apparently also died of FIP. I don't know the breeds of these latter two but the other four are all Birmans. So cetrainly here it seemed like it transmitted between cats - possibly susceptible individuals as three of them at least are related.

Re: FIP and pedigree cats

Richard Fox — Tue, 07 Dec 2010 13:04:11 GMT

In the literature, two FCoV biotypes have been distinguished: feline enteric coronaviruses (FECVs), which are endemic in cat populations and
generally not associated with clinical disease, and FIP viruses (FIPVs), which might arise from endemic FECVs either as an in vivo mutation or as virulent strains and are responsible for the development of FIP (Vennema, 1999; Brown et al., 2009; Pedersen et al., 2009; Chang et al., 2010). Regardless of the development of FIP, FCoV spreads from its initial site of infection within the intestine via monocyte-associated viraemia (Gunn-Moore et al., 1998; Kipar et al., 1999, 2005; Meli et al., 2004) and can replicate within monocytes in healthy cats (Can-Sahna et al., 2007).

I don't think they know but I would guess that it seems dependant on an altered FCoV strain and the individual immune response so even if the mutated virus is shed it would still require an altered immune response. I thought my colleague told be they had identifed an altered surface molecule that allowed entry to monocytes and thus determined FIP virulence?

I have emailed my colleague Dr. Kipar on this subject :)

Re: FIP and pedigree cats

Alex Allen — Tue, 07 Dec 2010 11:46:03 GMT

Useful references:

http://www.abcd-vets.org/index.asp - feline experts have reviewed and provided advice on the various infectious diseases including FIP

www.bvt.fr - For information on the BVT Speed diagnostic range including Diane Addie's evaluation of our F-Corona test

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2926681/pdf/VMI2010-809480.pdf - free review article on FIP diagnostic methods

http://www.dr-addie.com/ - Diane's website on FIP, feline viruses and FCGS

www.pubmed.gov - for many more papers - several are free and give an insight into this enigmatic disease.

Re: FIP and pedigree cats

Alex Gough — Tue, 07 Dec 2010 11:15:16 GMT

Richard, was there anything in the article about the transmissilibity of the mutated virus in the FIP infected cat (as opposed to the FCoV infected cat)?

alex

Re: FIP and pedigree cats

Richard Fox — Tue, 07 Dec 2010 10:53:48 GMT

FIP is associated with phlebitis and is thought to be a Type III hypersensitivity but virulence and FIP is associated with in-vivo viral mutation:

This article was co-written by a colleague of mine in Veterinary Pathology:

"Feline CoV (FCoV) is transmitted via the fecal-oral route and primarily infects enterocytes.²⁸ Despite the generally high prevalence of FCoV infection among the cat population, especially in multicat facilities, FIP morbidity is low and rarely surpasses 5%.^1,^7,²⁸ FIP seems to develop in the individual infected animal when FCoV acquires virulence by deletions in open reading frames 3 and 7, coding for nonstructural proteins of unknown function, which occur as mutations primarily during replication in the infected host.³⁹ Most infected cats develop an FCoV viremia that can be detected by reverse transcriptase-polymerase chain reaction (RT-PCR) on isolated (and cultivated) monocytes regardless of the development of FIP.^7,¹⁵ FCoV-infected circulating monocytes are considered as responsible for viral dissemination within the host.^10,^11,^28,⁴⁴ Furthermore, the demonstration of FCoV antigen within intravascular leukocytes and among cells in the lesions of vasculitis in a previous experimental study suggested that the infected monocyte mediates the development of FIP lesions.⁴⁴ The degree of macrophage infection and viral replication within infected cells in vitro, however, is associated with the virulence of FCoV strains.³⁵ Therefore, it seems likely that the development of FIP is related to the extent of monocyte infection.

On the other hand, the development of vasculitis and granulomas in FIP was previously attributed to a type-III hypersensitivity reaction.^10,²⁹ This hypothesis was based on immunofluorescence studies that showed cell-free fibrinogen and C3 as well as FCoV antigen, immunoglobulin (Ig)G, and complement within mono-nuclear cells in inflammatory lesions.^29,^43,⁴⁵ The demonstration of circulating immune complexes, high γ-globulin and C3 serum levels, and C3 deposition in glomerular mesangia have been interpreted as providing further support.¹⁰ However, neither the morphologic features of vasculitis in FIP nor its development has been thoroughly assessed and compared with unequivocal type-III hypersensitivity vasculitis.^4,^12,^13"

Also Healthy cats are thought to act as carriers:

Cats can be FCoV carriers and generally remain healthy, despite systemic infection. Previous studies indicate that FCoV persists within the intestine and is shed persistently or intermittently with the faeces . Therefore, persistently infected, healthy carriers are believed to play a key role in the epidemiology of FIP .

Re: FIP and pedigree cats

plantagenet — Tue, 07 Dec 2010 10:50:36 GMT

They intend to keep the new cat indoors.

Re: FIP and pedigree cats

Richard Carter — Tue, 07 Dec 2010 10:47:10 GMT

Possibly the wrong end of the stick but I was under the impression corona virus is basically ubiquitous and a negative titre would be potentially a high risk problem (similar to the medics and the way they react to titres against toxo - you should have been exposed to minimise the risk)

Re: FIP and pedigree cats

Alex Allen — Tue, 07 Dec 2010 10:11:03 GMT

Any responsible breeder would not object to a simple FCoV antibody titre test - these are cheap and can at least give an indication of whether there has been FCoV exposure. If titres are low then at least the probability of developing FIP is low.

In house FCoV tests now exist - eg Speed F-Corona but remember results must be interpreted with care. I know several cat breeders are using these tests to try and identify colonies where FCoV is present in an attempt to keep their colonies clean.

Re: FIP and pedigree cats

Peter Ding — Tue, 07 Dec 2010 10:06:54 GMT

Is not the real problem deciding whether to go for a cat with a persistent low titre for corona virus or one that has zero titre?

The latter will certainly be susceptible to catching corona virus and perhaps reacting in the way some do to develop FIP., whereas the former is perhaps less likely to get the condition.?

Although FIP tends to be associated with individual abnormal responses to a new infection of only some specific corona- viruses sub-types, corona viruses generally are widespread and cross-resistance is exhibited and it is difficult to distinguish between sub-types in the field.. Or is that not the current state of knowledge?

Trying to find a corona virus free breeder is not necessarily a solution unless the cat is to be isolated for evermore from others of its species.

Re: FIP and pedigree cats

Kate Richardson — Tue, 07 Dec 2010 10:02:36 GMT

I don't know any breeders per se, but they could try looking on the The Bengal Cat Club website- www.bengalcatclub.co.uk They are affiliated to the FAB and the Governing Council of the Cat Fancy so should find reputable breeders on there. Or The International Bengal Cat Society www.bengalcat.com which does have some UK breeders listed on it but seems more USA based.

However I would advise them that they can't get a 100% guarantee that they will not get FIP; too much is unknown about it, but they should speak to the breeder about their concerns and hopefully they will find someone who understands and has eliminated the risk as much as possible.

Re: FIP and pedigree cats

Derek Copeland — Tue, 07 Dec 2010 09:52:58 GMT

Responsible cat breeder !! now that would be a rare breed

Sadly my family have had personal experience of FIP Last year we lost a year old Burmese with FIP.I dont think breeders are aware or care about the sadness they cause to families or the fact that by continuing to breed when they kmow they have corona virus in their cats they are condeming a percentage of their kittens to a horrible death!

Surley any decent person let alone someone who "cares" about their "special" breed would take all steps necessary to stop these unnecessary deaths.

Yep very bitter !