MAJOR WinnerDavid Hughes (BSC BVSc Merit) &Rebecca Brady (BVSc Merit)

Rebecca Brady
graduated fromthe University ofSydney in 2012 andimmediately went
into co-ownership ofConcord Veterinary
Hospital with DavidHughes. She has
a strong passion
for feline internal
medicine, behavioural medicine and feline
welfare. She has gained a keen interest in feline
imaging—especially abdominal ultrasound. She
finds shelter medicine particularly rewarding
which is strengthened by Concord Veterinary
Hospital’s strong association with The Cat
Protection Society of NSW.

Overview
Feline infectious peritonitis (FIP) is a fatal diseasein cats whereby the relatively benign feline entericcoronavirus undergoes a mutation within a cat’s
own immune system—specifically within theirmacrophages—resulting in a disease known as FIP.
This mutation occurs in roughly 1 in 5,000 cats. FIP
can be categorised broadly into two syndromes—
wet FIP and dry FIP. Wet FIP is characterised bysingle or bi-cavitary effusions. Dry forms of FIP
are much harder to diagnose as symptoms andchanges on physical examination can be more
subtle. Some of the more obvious symptoms thatoccasionally occur in cases of dry FIP include
jaundice, enlarged mesenteric lymph nodes anduveitis—the disease often mimics lymphoma. FIP
generally affects kittens and cats under the age ofone; however, it can affect cats of all ages.

Diagnosing FIP
The diagnosis of FIP can at times be challenging.
The classical symptoms of wet FIP are a highfever non-responsive to anti-microbials, single
or bi-cavitary effusion, icterus and increased
globulins. Cases will often also be anaemic,
hypoalbuminaemic and have a significant
neutrophilia. The same set of findings can be saidfor dry FIP in the absence of an effusion—however,with additional clinical signs which may include

Est. 1965

David Hughes
graduated from theUniversity of Sydney
in 2010 and becamea practice ownerin 2013 at Concord
Veterinary Hospital.
The hospital has
a solid historicalaffiliation with The
Cat Protection
Society of NSW, providing a high feline caseload. David and his team have developed aninterest in canine and feline internal medicine
and ophthalmology. They have so far treatedover 20 feline infectious peritonitis cases
utilising this constantly evolving protocol.

Figure 1. A 1-year-old M(N) cat who was originallydiagnosed with lymphoma. The cat presented withenlarged mesenteric lymph nodes, enlarged liver,jaundiced, low albumin and high globulin and was
subsequently diagnosed with dry FIP—now over 6
months in remission after completing 84 days ofremdesivir. He was diagnosed based on his response toremdesivir.

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www.concordvets.com.au
C&T No. 5896

Centre for Veterinary Education

Concord Veterinary Hospital
191 Concord Road
North Strathfield NSW 2137
t. +61 2 9743 1715
e. concordvets@concordvets.com.au

Control & Therapy Series – Issue 304 September 2021

A FELINE INFECTIOUS
PERITONITISTREATMENTPROTOCOL

Page 7

Small

Entitled to a year's FREE CVE membership

Authors’ views are not necessarily those of the CVE

medium’ may be to make a presumptive diagnosis
based on symptoms and laboratory findings above,
then collect further samples for further analysis(outlined below) but commence treatment whilst
waiting for results as some of these results can takeup to 7 days.
It is important to note that there is no 100%
accurate test for ruling in or out FIP and there will
be times when it will come down to a clinician’s
judgement to diagnose FIP in a feline patient.
Often it comes down to a clinician’s level ofconfidence and experience treating FIP.
Further testing, when undertaken, can include:• Coronavirus PCR on cavity effusion by
IDEXX laboratories

Figure 2. A cat with wet FIP presenting with severe
jaundice and anaemia.

enlarged mesenteric lymph nodes, enlarged liver,changes to the kidneys on ultrasound, pulmonary
granulomas, and central and ocular signs if there isa neurological or ocular component such as uveitis,blindness, and seizures.
Often a presumptive diagnosis of FIP can bemade based on the above findings alone. Like any
disease, it is up to an individual clinician as to thelevel of proof they require before commencementof treatment of FIP.

Page 8Control & Therapy Series – Issue 304 September 2021

Further diagnostic testing can be carried out in an
attempt to confirm the diagnosis of FIP, and someclinicians feel these tests need to be run prior tocommencement of treatment. Perhaps a ‘happy• Immunofluorescence assay on cavity effusionby the University Veterinary Teaching Hospital
Sydney (UVTHS)• Immunocytochemistry on FNA samples of tissue
aspirates by UVTHS, and• Immunohistochemistry can be performed on
tissue samples collected at ex-lap by UVTHS.

The Concord Veterinary Hospital
Treatment Protocol
This article will discuss the use of a drug called
remdesivir.

To recap—the common findings with both
wet and dry FIP:
1.
2.
3.
4.
5.
6.
7.

Figure 3. Icteric blood after centrifugation from theabove jaundiced wet FIP cat. Note how anaemic thesample appears to be also.

Uni or bicavitary effusion (Wet only)
High fever not responsive toantibiotics
Hyperglobulinaemia
Hypoalbuminaemia
Icterus
Non-regenerative anaemia
Neutrophilia

As per previous communication distributed by
Richard Malik, one way to ‘diagnose’ FIP in cats,
especially dry forms of FIP, is to trial patients on
3–4 days of remdesivir and if a rapid improvement
in clinical signs is seen (reduction in mesentericlymph node size, resolution of fevers, regaining ofappetite) then the diagnosis of FIP is essentiallyconfirmed.

The First 3 to 4 days
The earlier treatment is commenced, the betterthe outcome—and this cannot be overstated. There
are two options for commencing treatment and likemost things in life it often comes down to budget.

Figure 4. Collecting abdominal fluid from a wet FIP
patient to submit a sample for immunofluorescenceassay to VPDS, SSVS.

What is Remdesivir?
Remdesivir is a broad-spectrum antiviraldeveloped by the pharmaceutical companyGilead. Remdesivir was originally developed totreat Hepatitis C and Ebola Virus; however, it wasfast-tracked and given approval in many countries
worldwide for the treatment of COVID-19. Its use
now in COVID-19 patients is controversial; however,
it is showing amazing promise for the treatment ofFIP in cats.

Treatment with Remdesivir

2.The intravenous RouteIf a patient is unwell, or neurological orocular FIP is suspected, then they should be
hospitalised, placed on intravenous fluids,
run at a quarter to a half maintenance rates(Hartmann’s or similar is fine). The reason forsuch a low rate will become clear shortly, andremdesivir administered SLOW IV (over 10minutes is fine) for 3–4 days. We have found
if you can maintain your catheter to a fourth
day it is great to get a fourth intravenous dose
into your patient; however, if there is pain at
the cannula site or thrombophlebitis, then 3days is fine.
The downside to administering remdesivir
intravenously is obviously having to hospitalise thepatient, the added expense to the owner which is
not insignificant and also there is an increased risk(10% risk) of developing or worsening of a pleural
effusion with the use of intravenous remdesivir,

Figure 5. A F(S) Bengal cat with ocular and central FIP
before treatment with remdesivir. Note the dilated
pupils. This cat was centrally blind prior to treatment.

Figure 6. The same Bengal some 4 – 6 weeks later after
treatment with remdesivir with a normal ocular exam
and apparent full vision.

Page 9Centre for Veterinary Education|Est. 1965

Treatment with remdesivir is for 84 days bysubcutaneous injection, so it requires a committed
owner or a sympathetic veterinarian geographicallyclose by. Remdesivir can be sourced readily fromBOVA Compounding Pharmacy who ship Australiawide normally overnight. The cost of the drug issignificant; the vials are 100mg/vial at $275/vial
inclusive of GST. The final concentration is 10mg/mL. Needless to say—treatment of FIP by an ownertakes a lot of financial and emotional commitment.

If a patient is stable and eating—subcutaneous
injections can be commenced at a dose rateof 10mg/kg and the patient checked daily
for the first 3–4 days. This is a perfectly
acceptable routine for a well-hydrated
patient who is eating, and is the morefinancially sustainable option.

Control & Therapy Series – Issue 304 September 2021

1. Subcutaneous Injections

Authors’ views are not necessarily those of the CVE

mostly in wet forms, which then requires closemonitoring by either regular thoracic radiography
or T-Fast ultrasonography daily or twice daily (weprefer twice daily).
The benefits of intravenous remdesivir are you geta high anti-viral dose to target the virus for theinitial 3–4 days, you get to observe your patientand more often than not get to see the fever breakin front of your eyes and to see a near moribund
patient ‘come back to life’ and show signs ofimprovement daily!
Obviously, this is a conversation to be had witheach individual owner and for the clinician tomake on a case-by-case basis. See below for otherconsiderations before deciding which patientswould or would not benefit from intravenous
remdesivir therapy.
Cats receiving intravenous remdesivir do not need
to be in a 24-hour facility—remdesivir could be
administered intravenously in the mornings so aclinician then has the whole day to observe theirpatient. We have also heard examples of veterinary
hospitals administering the intravenous remdesivir
and then sending the patient home for the nightwith the indwelling intravenous catheter in place so
the owner can monitor the cat for the night in caseof emergency and to keep costs down.

Page 10Control & Therapy Series – Issue 304 September 2021

Days 5 to 84
Remdesivir needs to be given at a dose of 8–10mg/kg subcutaneously once daily for 84 days in total.
We would encourage dry forms to be dosed at
10mg/kg (ocular and neurological forms often
require 15mg/kg) and wet forms 8mg/kg. In ourexperience there is a tendency for vets to reducethe dose of remdesivir prematurely. Do not doseto lean body mass or try and assume what akitten might weigh without its effusion—kittens
metabolise drugs faster so need a higher dose.
Simply dose them for their weight—keep it simple.
Do things to encourage success in your patientsfor injections. For example; remdesivir is stored
in the fridge. However, it is fine for it to come toroom temperature before injection; this will help
minimise the pain with the injection. We havefound 22G needles minimise pain for injection;
however, some cats prefer 23G or 25G—it really is agame of trial and error.
Some cats need to come into the vet every
day for their injection. Even this shows serious
commitment by the owner! Furthermore, somepatients require the use of buprenorphine prior
to their injection, especially as they approach theend of the course of their 84 days. Gabapentin
orally prior to injection has been trialled with lesssuccess but is still worth a try in some cases.

It is worth noting at this point we are often
dealing with kittens here – so ensure they
are being weighed regularly and their doseof remdesivir is being adjusted upwards
accordingly to 8–10mg/kg.

Monitoring
Do not fall into the trap of doing blood work ondays 1-3 after commencing treatment—nothing will
have changed.
Once again, the bloods that are performed dependon the financial limitations of your client. Ideally,
we like to perform a CBC and Biochemistry panel(including bilirubin and globulins) at week 4, week
8 and week 12. We are looking for resolution ofanaemia, reduced neutrophils, normal albumin andglobulin and normal bilirubin.
In theory you could also simply perform a PCV, TPP
and a globulin level. This will give you an idea of
the anaemia, the colour of the serum to check ifyour patient is still jaundiced, the albumin and theglobulin level by simple calculation.

When Does Treatment End?
We get asked this question a lot.

Treatment ends when:
1. ALL blood parameters are WELL
within normal limits including
globulins.
2. All effusions are absent.
3. Lymph nodes are normal
4. There are no central/ocular signs.

At this point, we call them ‘cured’.

But How Long Do They Last and How
Many Have Died?
It is still extremely early days. The answer is we
simply do not know. We estimate the efficacyof remdesivir to be 80-95%. Wet has a better
prognosis than dry for example, and neurologicalhas a worse prognosis than non-neurological.
We will only comment on our cases as we havedeveloped our regime. Of some 20 cases—1 case
was lost as it presented moribund and unable tobe saved, 1 case was lost that had concurrent FIV,
the FIP was ‘cured’; however, the cat went on toa good sign. It is recommended to NOT drain
the abdominal fluid unless to get diagnostic
samples or for urgent therapeutic reasons (e.g.
if dyspnoea is severe due to pressure onto thediaphragm).

5

10 Important Points About the Use ofRemdesivir:

1

2
3

THE MOST IMPORTANT POINT TO NOTE:
10% of cats receiving intravenous remdesivir
can develop pleural effusions—especially wetform. Therefore, cats receiving intravenous
remdesivir need to have serial radiographs
and/or skilled T-Fast ultrasonography on a daily
or bi-daily basis. Pleural effusions are more
likely if a clinician pushes the intravenous fluid
administration beyond maintenance—we preferto keep the fluid rate below half maintenance.
Many patients will become quiet for 1–3 hours
after receiving remdesivir intravenously—theexact mechanism is unknown but do not be too
alarmed if this occurs.
Wet cases: the ABDOMINAL effusion willoften get worse before it gets better. This is678Globulins will often go up at the first blood test
before they begin to come down. Do not getdisheartened.
Many vets are concerned about the reportsof elevations in kidney and liver parameterswith the use of remdesivir. There have beena few reports of elevations in SDMA andoccasional reports of elevation in ALT withdoses of remdesivir as high as 15mg/kg that
resolved once the dose was resumed tonormal. The authors have had 2 cats on 15mg/kg of remdesivir and has not personally seen
elevations in ALT (but have not checked SDMA
for various reasons).
Antibiotics: Often FIP cats have comorbidities
with infections which require treatment withantibiotics. Infections such as Mycoplasma arecommon. Antibiotics such as doxycycline areoften a good choice. Other antimicrobials—
if indicated —do not appear to becontraindicated.

Est. 1965

4|

It is worth noting—we have 2 cases currently, bothdry—where we have been unable to reduce theglobulins to a normal level beyond 84 days, so wehave had to increase the dose to 15mg/kg, andboth are well over 110 days treatment but are doing
well. The likely cause for both of these prolonged
and ‘unsuccessful-so-far’ cases has been areduction in dose from 10mg/kg to 6mg/kg. We
would advise against this—especially in dry forms.

Centre for Veterinary Education

develop mediastinal lymphoma, and 1 kitten was
put to sleep for presumed septicaemia. The othercases are at various stages of remission or still intreatment.

Control & Therapy Series – Issue 304 September 2021

Figure 8. The same domestic shorthair cat with dry FIP
just 4 weeks into treatment with remdesivir.

NSAIDs to bring fevers down are often NOT
required with the use of remdesivir.
The concurrent use of corticosteroids withremdesivir is not strictly contraindicated;
however, it is not recommended. If your patient

Page 11

Figure 7. A M(N) 12-week-old domestic shorthair with dry
FIP – they generally just look ‘poorly’ with a fever thatpersists.

is on corticosteroids we would recommend
weaning them as quickly as is safe to do so.

Page 12Control & Therapy Series – Issue 304 September 2021

Authors’ views are not necessarily those of the CVE

910Remdesivir can occasionally sting as aninjection, so our clients need our help withrespect to teaching them how to administer
the drug and pointers on how to minimise thesting (needle choice size, allowing the drug tocome to room temperature prior to injection,utilising medications such as buprenorphineprior to injection). The drug itself doesn’t
appear painful—it is the repeated injections
and the amount of liquid that needs to be
injected daily. weaning them as quickly as issafe to do so.
Often it can be beneficial to a patient tocommence a treatment trial of remdesivir tosee if a presumptive diagnosis can be made of
FIP or whilst waiting for further diagnostics toreturn from the lab.
eBook download
C&T 5883 Feline Infectious Peritonitis(FIP)—Now a treatable disease.
Jane Yu, Merran Govendir, Sally J Coggins &Jacqueline M. Norris, Issue 303 June 2021.

PLEASE CONTACT US

if you'd like to be a part of thesetrials
Two clinical trials for naturally occurring
FIP infected cats have commenced at theSydney School of Veterinary Science atThe University of Sydney and are recruiting
Australia-wide:• one looking at mefloquine, withand without interferon• the other looking at Remdesivir

And/Or you need advice for asuspected or confirmed FIP CaseJacqui Norris atjacqui.norris@sydney.edu.au
Sally Coggins atsally.coggins@sydney.edu.au