FIP Flashcards
What is FIP?
An immune mediated disease trigger by feline coronavirus infection
Mostly cats 3m-3yr with a second peak over 10 years, although 50% are < 1 year
More common in purebreeds
1 in 5000 in 1-2 cat households
Up to 5-10% in catteries
What are the clinical forms of FIP?
Non effusive (dry) form – partial CMI response
Granulomatous inflammatory lesions in several organs
Effusive (wet) form ‐ no immune response fibrinous to granulomatous serositis –> body cavities get accumulation of protein‐rich fluid
Mixed form
What is FIP associated with leukocyte wise
Profound T cell deficiency
What are the possible clinical signs of FIP?
Lethargy, inappetence, fluctuating fever
Weight loss, abdominal distension, stunted growth
(kittens)
Tachypnoea, respiratory distress
Testicular enlargement
Pericardial effusion, cardiac tamponade
Organomegaly
Ocular signs
Neurologic signs
Skin lesions
What are the occular signs possible?
Can occur without systemic signs
Pyogranulomatous uveitis: retinal vasculitis, haemorrhage & detachment with exudative subretinal fluid
Anterior segment lesions: acqueous flare, keratic precipitates, hyphema, hypopyon, miosis, swollen iris, synechiae, and hypotony.
Non effusive form
What neuro problems can FIP cause?
Meningoencephalitis,
meningomyelitis,
Ependymitis and choroiditis, can lead to obstructive hyrocephalus
10% of FIP cats have neuro problems
50% of inflammatory/ infectious feline neuro problems = FIP
What neuro signs can be seen?
Inappropriate elimination Behavioural changes Dementia Cerebellar‐vestibular signs (++) Seizures Hyperesthesia (physical and auditory) Hyper‐reflexia Crossed‐extensor reflex Reduced conscious proprioception Caudal paresis
Outline seizures associated with FIP
Generalised tonic‐clonic seizures
Complex focal seizures
Status epilepticus
Don’t tend to see clusters
Shows extensive forebrain lesions (and therefore px worse)
What derm signs can be seen?
Rare Scrotal swelling Skin fragility Nodules (pyogranulomatous inflammation) Lesions associated with debility
Outline skin fragility syndrome
Other ddx: diabetes mellitus, progestational drugs, HAC, hepatic lipidosis, cholangiocarcinoma, FIP.
Fragile thin skin, tears with minor trauma
Histology: Thin epidermis, severe dermic atrophy
Outline the histology of skin nodules/ papules etc
pyogranulomatous vasculitis & mural folliculitis, phlebitis & periphlebitis
Skin lesions may facilitate a definitive diagnosis through biopsy
How do you diagnose FIP
Definitive diagnosis by IHC for Coronavirus Antigen (histology)
Presumptive diagnosis:
History & Signalment
Clinical and laboratory findings
outline the main considerations when trying to diagnose FIP
Effusions often have the best predictive value
Aim to rule out HCM, liver disease and neoplasia with bloods and imaging
What notes in the hx may make FIP a dx to consider
Been in a multicat household, from cat breeder, human shelter, in previous 6‐12 months
Stressed in previous 1‐12 months (eg was rehomed, was neutered, gave birth…)
What haematology and biochemistry findings are suggestive?
Haematology
Lymphopenia, non regenerative anaemia, left shift neutrophilia
Blood and effusion biochemistry A:G ratio: <0.4 (+++), >0.8 (‐‐) Globulin: >35 g/l (+++) <25 g/l (‐‐) α1‐acid‐glycoprotein: >1500 μg/ml (+++) <500 μg/ml (‐‐) Indicators of organ damage (e.g. high bilirubin)
What are the ddx for hypergammaglobulinaemia?
Lymphoma
Multiple myeloma or plasma cell tumour
Chronic infections
FIV
What serological testing is available for FIP?
IFAT – Indirect Immunofluorescent AntibodyTest
ELISA – Enzyme Linked Immunosorbent Assays
RIM – Rapid Imminochromatographic tests
Immunolotting (Laboratory only)
Specificity 100% for most tests
Sensitivity 100% for some IFA test and ELISA
What does FIP fluid look like on assessment?
Fluid is clear, straw coloured, clots on standing, froths if shaken
Cytology of effusion:
Low cellularity (<5000 nc/μl)
Macrophages & neutrophils (++)
Immunofluorescence of macrophages in effusion -Positive
Rivalta test - Positive
When will you get a false positive Rivalta test
bacterial peritonitis
Lymphoma
What is the best acute phase protein to test for in an effusion or serum?
a1 acid glycoprotein
What is the sensitivity and specificity of the Rivalta test?
Positive predictive value (86%)
Negative predictive value (96%)
how useful is virus detection (RT-PCR)
Can’t distinguish between virulent and avirulent strains
Compare serologic testing and organism detection
Serological testing checks for ABs and does not equal a dx of FIP
Organism specific identification (Histopathology findings) and Immunostaining (IHC and ICC) allow a definitive diagnosis
What would you expect to see on CSF analysis?
protein (30‐1000 mg/dl, ref <25)
total nc (20‐10000 cell/ul)
Neutrophils (++), lymphocytes, macrophages
Positive immunocytochemistry of CSF macrophages
What immunosuppressives can you use for treatment?
Prednisolone 1‐2 mg/kg PO SID/BID
Dexamethasone IT or IP q24h until no effusion
Chlorambucil 2 mg/cat PO q48‐72 h
Cyclophosphamide 2.5 mg/kg PO q24 h for 4
consecutive days every week
What is the evidence for antivirals?
V limitted
What should be done if a cat dies from FIP
In single cat household - do not get another cat for at least 2 months
Multicat households - reduce stress/ overcrowding as much as possible
How useful is the FIP vax?
Little help
May even lead to Antibody‐dependent disease
Enhancement (ADDE) - speeds up progression of disease in those infected
