Feline Infectious Disease Flashcards
when is infectious feline upper respiratory tract disease common?
in multi-cat environments (e.g multi-cat households/shelters)
stressed cats
what are the most prevalent causes of infectious feline upper respiratory tract disease?
feline herpes virus (FHV-1) feline calicivirus (FCV)
what are the less common causes of infectious feline upper respiratory tract disease?
chlamydia felis
Bordetella brochiseptica
secondary bacterial infections
what are the main symptoms of infectious feline upper respiratory tract disease?
watery discharge from nose and eyes with staining
inappetance
snuffly
ulcers in mouth / on tongue
what tends to cause the most severe infectious feline upper respiratory tract disease?
viral agents esp. FHV
what type of virus is FHV-1?
enveloped DNA virus
what happens to cats post FHV-1 exposure / infection?
most cats become latent lifelong carriers
where is FHV-1 carried in the cat?
trigeminal ganglion within the face
what can trigger shedding of FHV-1?
stressful event e.g. other illness, immunosuppression, new family member
when is shedding of FHV-1 triggered?
4-12 days post stressful event
how long do cats shed FHV-1 for?
~1 week
will cats show clinical signs when shedding FHV-1?
not always - may be silent shedders
how is FHV-1 spread?
close contacts
phomites
what type of virus is FC?
non-enveloped, single stranded RNA virus
how long does FC last in the cat post infection?
up to 1 month in oropharyngeal tissues
where does FC persist following infection?
oropharyngeal tissues
how long does carrier state of FC last?
most cats around a month - some may be lifelong carriers
when does shedding of FC occur following infection?
continuously - may be asymptomatic
how is FC spread?
phomite
close contact
aerosol also possible
where are infectious agents of both FHV-1 and FC found?
in respiratory secretions - oculo-nasal discharge, saliva
what cells of the naive cat are targeted by FHV-1 and FCV?
upper respiratory tract epithelial and lymphoid tissue
where else does FCV replicate?
systemic tissues
where is FCV also shed?
urine and faeces of infected cats
how long is the incubation period of FHV-1 and FCV?
2-6 days
when does viral shedding of FHV-1 and FCV occur after infection?
1 day - before the clinical signs
when are clinical signs seen after infection with FHV-1 and FCV?
2-6 days
what is the range of symptoms seen with FHV-1 and FCV?
can be very mild to severe and life threatening
what animals suffer more severely with FHV-1 and FCV?
kittens and immunocompromised patients
what can FHV-1 and FCV symptoms be exacerbated by?
secondary opportunistic infections caused by damage to tissues by initial virus
where are main symptoms of FHV-1 and FCV seen?
oral
nasal
occular
some systemic (FCV)
what are dendritic ulcers pathognomic for?
FHV-1
what oral lesions are seen with FHV-1 and FCV?
gingivostomatitis
what is gingivostomatitis?
inflammation of gingiva and oral mucosa generally
what oral lesions are seen with FCV?
lingual ulcers
where can samples be taken from to diagnose FHV-1 and FCV?
conjunctival or pharyngeal swabs (depending on area most affected)
what tests may be used to diagnose infectious feline upper respiratory tract disease?
PCR
virus isolation
culture
what test is most sensitive to FCV?
virus isolation
what cause of infectious feline upper respiratory tract disease is usually diagnosed by culture?
C.felis
B.bronchoseptica
what infectious feline upper respiratory tract disease can PCR show?
all 4: FHV-1, FCV, C.felis, B.bronchosepta
what supportive therapies are needed for treatment of infectious feline upper respiratory tract disease?
fluid therapy
nutrition
what specific medications might be needed for treatment of infectious feline upper respiratory tract disease?
antivirals
antibiotics for secondary infections
analgesia
appetite stimulants
what are the key elements of nursing care for patients with infectious feline upper respiratory tract disease?
clean face with warm, wet swab
barrier creams
occular lubricant
nebulisation to loosen secretions
why is cleaning the patients face with a warms wet swab necessary when they are suffering with cat ‘flu?
improved comfort
improved smell
what is the role of barrier creams in the patient with infectious feline upper respiratory tract disease?
prevent scald caused by discharge from nose and eyes
what should not be used on cats with cat flu?
olbas oils / human cold remedies as they are highly irritant to nasal mucosa
why should injectable meds be given to infectious feline upper respiratory tract disease patients where possible?
due to oral ulcers they may find oral handling undcomfortable
why should cats with infectious feline upper respiratory tract disease be restrained without hands under mouth/near neck?
altered head position may lead to pharyngeal obstruction which can cause difficulty breathing
what must be corrected in the first 24-48hrs of infectious feline upper respiratory tract disease treatment?
dehydration and electrolyte imbalance
what method of eating is preferred in patients with infectious feline upper respiratory tract disease?
orally
what should patients with infectious feline upper respiratory tract disease be fed?
small volume, palatable, warm foods
how often should infectious feline upper respiratory tract disease patients be fed?
4-6x a day
when should uneaten food be removed from a cats kennel?
after 20-30 mins as may increase nausea and stress levels
what drugs may be used to aid nutrition?
anti-emetics and appetite stimulants
how may severe flu cases need to be fed?
tube feeding - meds can also be given this way
what antiviral drugs are used to treat recurrent or severe FHV-1?
Famciclovir
what is the effect of Famciclovir?
clinical improvement and reduced shedding of virus
what antiviral drugs are used in FHV-1 cats with conjunctivitis?
Lysine
how does lysine work?
antagonises arginine which is needed for FHV-1 replication
what is the role of Lysine?
improves conjunctivitis in FHV-1 cats
reduces FHV-1 shedding
what is the role of recombinant feline interferon gamma?
significantly improves refractory stomatitis in FCV infected cats
when should secondary bacterial infections be suspected alongside infectious feline upper respiratory tract disease?
if thick, mucopurulent discharges present
what tests should be performed if secondary bacterial infection alongside infectious feline upper respiratory tract disease suspected?
culture and sensitivity
what antibiotic is the best for both C.felis and B.bronchiseptica?
doxycycline
what is the alternative antibiotic that can be given if Doxycycline is contraindicated?
Amoxycillin clavulanate
what are the issues with Doxycycline as an antibiotic?
not ideal with anorexic patients and there is risk of oesophageal stricture if drug remains in the oesophagus for a prolonged period
what other medication may be given to patients with infectious feline upper respiratory tract disease?
analgesia
mucolytics
what type of analgesia is most commonly used for infectious feline upper respiratory tract disease patients?
opioids
why may NSAIDs not be a suitable analgesic for infectious feline upper respiratory tract disease patients?
if corneal ulceration is present NSAIDs may suppress the helpful inflammatory response
what are mucolytics?
substances which break down mucous
when can mucolytics only be used?
if animal is unable to clear mucous themselves as will make runnier mucous worse
give an example of a mucolytic
bromhexine
how can the environment that a cat with infectious feline upper respiratory tract disease has been in be managed?
thorough cleaning
disinfection of fomites
cages
how long does FHV-1 survive for?
18 hours at room temperature
how can FHV-1 be inactivated?
by most disinfectants and drying
how long does FCV survive in the environment?
up to 1 month / longer in dry conditions
what cleaning agents can be used to kill FCV?
bleach
accelerated hydrogen peroxide
what disinfectant agents are FCV resistant to?
QAC
which animals should be placed in isolation facilities?
clinically affected patients
suspected carriers
when should infectious patients be handled?
last
what sort of nursing is required for infectious feline upper respiratory tract disease patients?
barrier nursing
what should be done about infectious feline upper respiratory tract disease patients if isolation facilities are not available?
barrier nursing
house respiratory cats at one end of ward
sneeze barriers
if cages are facing each other there should be 2m between
disinfect cage at end of stay and leave empty for 2 days
what is the role of FHV-1/FCV vaccines?
reduces incidence and severity ofdisease
what do FHV-1 and FCV vaccines form part of?
CORE vaccines
what immunity is gained from FHV-1 and FCV vaccination?
local humoral (IgA) and cell mediated immunity
how long does maternally derived FHV-1 and FCV immunity last?
6-16 weeks
what are the 2 types of FHV-1 / FCV vaccines available?
attenuated live or inactivated
what type of FHV-1/FCV vaccine be used wherever possible?
attenuated live
when can inactivated FHV-1/FCV vaccines be used?
immunosuppressed and pregnat cats
when can kittens be vaccinated against FHV-1/FCV?
6-8 weeks
how does the initial course of FHV-1/FCV vaccines work?
from 6-8 weeks
every 3-4 weeks
until at least 16 weeks
when should cats be re-vaccinated for FHV-1/FCV?
every 1-3 years after
when should queens also be vaccinated against FHV-1/FCV?
prior to mating
how can FHV-1/FCV be prevented?
minimise stress
avoid overcrowding
quarantine new additions to multi-cat households for 3-4 weeks
don’t breed from clinically infected queens
consider early weaning (although could be detrimental) if outbreak
how can FHV-1/FCV be prevented in catteries?
house cats individually unless from same household at home
impermeable sneeze barrier
over 4ft apart
what are the signs of highly virulent calicivirus?
upper respiratory disease (as for FCV)
cutaneous signs - especially head and limbs
what are the cutaneous signs of highly virulent calicivirus?
ulceration
crusting
alopecia
oedema
what severe signs may a cat with highly virulent calicivirus exhibit?
sever respiratory signs - pulmonary oedema and pleural effusion
hepatic and pancreatic involvement - icterus, vomiting and diarrhoea
marked pyrexia, anorexia, lethargy and weight loss
what can highly virulent calicivirus result in?
peracute death (sudden)
what type of bacteria is Chlamydia felis?
obligate intracellular bacteria
what are the 2 forms of Chlamydia felis?
elementary body (EB) - infectious form reticulate body (RB) - non infectious form
how are C.felis bacteria elementary bodies transmitted?
via direct contact, fomites and aerosols
how long doe C.felis survive in the environment?
a few days
what disinfectants is C.felis susceptible to?
most disinfectants
what happens to EB C.felis when it attaches to host epithelial cells?
internalised into inclusion and morphs into RB
what does RB C.felis do?
replicates in host cells, matures to EB and is released from cells
what is the incubation period of C.felis?
2-5 days
what is the key sign of C.felis?
severe conjunctivitis
what cats are typically infected by C.felis?
young cats (<1 year) from multi cat households
what are the main clinical presentations of C.felis?
feline conjunctivitis (acute/chronic/recurrent) upper respiratory signs corneal ulceration (rare)
how is C.felis diagnosed?
PCR from conjunctival swabs
how is C.felis treated?
oral doxycycline for 4 weeks
at least 2 weeks after clinical resolution
in cattery all in contact cats should be treated
is a vaccine for C.felis available?
yes - non core
what type of bacteria is B.bronchiseptica?
aerobic, gram negative, cocco bacilli
where may B.bronchiseptica be found?
clinically healthy dogs and cats as well as those with respiratory disease
where is B.bronchiseptica most prevalent?
high density populations e.g. boarding kennels/catteries
how long does B.bronchiseptica persist in the environment?
~10 days
what disinfectants are B.bronchiseptica susceptible to?
most
how is B.bronchiseptica passed on?
airborne
fomites
infected water sources
what is the incubation period of B.bronchiseptica?
2-10 dasy
hwo does B.bronchiseptica lead to secondary infections?
respiratory colonisation leads to inflammation and so increased mucus production. This impairs host defences and so increases susceptibility to secondary infections
how does B.bronchiseptica infection most commonly present?
upper respiratory tract and large airway disease
what are kittens with B.bronchiseptica susceptible to?
pneumonia
what are the signs of B.bronchiseptica?
sneezing
mucoid/mucopurulent nasal discharge
harsh cough
how is B.bronchiseptica diagnosed?
use of brochoalveolar lavage fluid
culture and sensitivity
PCR
how can B.bronchiseptica be treated?
doxycycline 1-4 weeks
is there a vaccine for B.bronchiseptica?
yes - intranasal (non core)
what type of viruses are FIV and FeLV?
enveloped RNA
what are retroviruses?
viruses with RNA which is reverse transcribed within the host to produce proviral DNA
how well do FIV and FeLV survive outside the host?
poor survival - rapidly desiccated, inactivated by disinfectants
how does a cell become persistently infected with FIV and FeLV?
virus fuses with host cell membrane
viral reverse transcriptase enzyme converts RNA to proviral DNA
provirus integrated into host genome leading to persistent infection
what viral enzyme converts RNA to proviral DNA?
reverse transciptase
what part of the FIV and FeLV genome encodes core viral proteins?
gag
what is an example of a gag gene in FIV?
p24
what part of the FIV and FeLV genome encodes enzymes (including reverse transcriptase)?
pol
what part of the FIV and FeLV genome encodes envolope glycoproteins?
env
what is an example of a gag gene in FeLV?
p27
what is an example of a env gene in FIV?
gp40
what is an example of a env gene in FeLV?
gp70
what is FIV similar to?
HIV
is FIV zoonotic?
no
do all cats with FIV develop AIDS?
not all
what is the survival rate of cats with FIV?
comparable to those without FIV
how does the pathogenicity of FeLV compare to FIV?
more pathogenic
what does the increased pathogenicity of FeLV mean?
more direct association with clinical disease than FIV
what clinical disease does FeLV lead to?
bone marrow disorders
haematopoietic neoplasia
immunosuppression
how is FIV transmitted?
bite wounds (high conc. in saliva)
infected blood products
some vertical transmission (~1/3 of kittens born to an infected mother)
how is FeLV transmitted?
allogrooming - prolongued oronasal salivary exposure
fomites
vertical transmission effective
infected blood products
what is the signalment of FIV?
fighters
outdoor access
older
male
what is the global seroprevalence of FIV?
1-12% (lower end in pets, higher in feral)
what is the signalment of FeLV?
close contact cats
outdoor access
median age ~3
entire
what is the global seroprevalence of FeLV?
1-6%
what has caused a decline in global seroprevalence of FeLV?
vaccination (in core program)
what is the effect of age on FeLV infection?
infection as an adult is less likely to lead to disease than in a younger cat (age related immunity)
what is clinical course of FIV comparable to?
HIV / AIDS
how long does FIV infection last?
lifelong as virus is integrated into host genome
what is commonly seen in cats with FIV?
prolonged (years) asymptomatic phase
what happens in the acute pahse of FIV infection?
virus replicates in local lymphoid tissue and leads to transient lymphadenopathy (large firm lymph nodes)
when does peak viraemia of FIV occur?
8-12 weeks post infection
what are the signs of peak viraemia of FIV?
transient illness - lethargy, pyrexia, inappetance, GI signs, weight loss
is illness around peak FIV viraemia often noticed by owners?
no - often undiagnosed at this stage
following acute FIV infection what can happen?
asymptomatic phase which lasts lifetime
asymptomatic phase which then leads clinical / terminal phase
what cells are particularly targeted by FIV?
CD4 T cells
what is the effect of FIV infection attacking CD4 T cells?
impaired response to infectious agents
what is often seen in the terminal phase of FIV?
chronic gingivostomatitis opportunistic infections neurological disease neoplasia myelosupression
when will viral load of FIV begin to climb after the initial peak load around 8-12 weeks post infection?
when CD4 t cell number become so low that the immune system can no longer suppress the virus
what happens to viral load following acute phase of FIV?
immune system will suppress virus for a while
what are the clinical signs of FIV?
predisposition to secondary infection
neoplasia
occular lesions
anaemia
what cats are commonly screened for FIV (and FeLV)?
sick cats
what do FIV screening tests detect?
antibodies against FIV
what does a positive result on an FIV test indicate?
FIV infection (based on 2 key assumptions)
what are the 2 key assumptions that a positive FIV result is based on?
no history of vaccination
cat is older than 6 months
why will vaccination history affect FIV test results?
vaccine will induce antibodies and these will be detected by the test
why will the age of a kitten affect the result of an FIV test?
kittens may acquire maternal antibodies through colostrum
how should a positive FIV result be confirmed?
by using a test from a different manufacturer or a different test type (especially when screening a well cat)
when is FIV more likely to be the cause of a current illness in the cat?
if immuno-incompetancy or lymphoma is a feature of the current disease
what may cause false negative FIV test results?
in early disease
in terminal disease
kittens with rapidly progressive disease
why may a FIV test give a false negative in early disease?
takes up to 8 weeks for antibodies to be detectable
why may a FIV test give a false negative in terminal disease?
antibody production may be impaired at this stage
why may a FIV test give a false negative in kittens?
may have large viral burden with minimal antibody response
what should you do if suspicious of a false negative FIV test?
re-check 2 months later use PCR (blood) to check for DNA
when should cats be tested for FIV outside of sickness?
known exposure to FIV+ cat before rehoming to muti-cat household blood donor screening before FIV vaccine seropositve kittens <6 months old
what should seropositve kittens <6 months old be retested?
> 6 months
what is the outcome if a FIV seropositve kitten <6 months old becomes negative when retested?
FIV negative result - positive was due to maternal antibodies
what are the clinical signs of initial FeLV infection?
nonspecific clinical signs (inappetance, pyrexia, lethargy)
how is FeLV shed during the infection period?
salivary shedding mainly along with urinary and faecal
what are the 3 possible outcomes of FeLV infections?
abortive infection
regressive infection
progressive infection
what will lead to an abortive FeLV infection?
strong immune response
what does abortive infection mean in terms of FeLV immunity?
animal becomes immune to FeLV
how is FeLV regressive infection caused?
ineffective immune response which leads to haematogenous spread in the blood. This then causes bone marrow infection which is suppressed by an effective immune response but as the infection has already entered the blood stream regressive infection will follow at some point (either immediate or delayed)
when will bone marrow infection with FeLV occur?
approx 3 weeks post infection
what causes progressive FeLV infection?
inadequate immune response
established bone marrow infection
what does progressive FeLV infection lead to?
persistent viraemia
manifestations of FeLV related disease
what are the main clinical manifestations of FeLV?
anaemia / bone marrow disorders
neoplasia
immunosuppression
other
what infections can arise from FeLV associated immunosuppression?
opportunistic
gingivostomatitis
FHV and FCV
Mycoplasma haemofelis
what are the effects of FeLV associated immunosuppression on treatment and vaccine response?
respond less well to therapy compared to healthy cats
have impaired response to vaccinations
what type of anaemia is most common in FeLV?
non-regenerative macrocytic
why is macrocytic non-regenerative anaemia in FeLV so significant?
unusual to see macrocytic non-regenerative anaemia
what is regenerative anaemia linked to FeLV often caused by?
IMHA
Mycoplasma haemofelis
what are the main FeLV related anaemia and bone marrow disorders?
anaemia (non-regenerative most common)
neutropenia
thrombocytopenia
various severe and pre-malignant bone marrow disorders
what is the most common FeLV related neoplasia?
lymphoma
leukaemia
what is the risk increase associated with lymphoma in FeLV cats compared to healthy cats?
60% risk increase
what is the normal age of FeLV lymphoma cats?
young
what type of lymphoma is strongly associated with FeLV?
thymic
why are most cats with lymphoma FeLV negative now?
due to FeLV vaccination and so low prevelance
List 5 other FeLV associated diseases
Ansocoria reproductive failure neurologic signs immune-mediated diseases GI signs
how is FeLV diagnosed?
screening blood tests
what is an example of a test for FeLV?
ELISA for FeLV antigen (capsid protein)
what should be done if a FeLV positive result is gained in a healthy or sick cat?
repeat test
what should be done to confirm a FeLV positive result in a sick cat?
repeat with a different test manufacturer or methodology
how should a cat be evaluated for FeLV regressive infection if healthy?
4-6 month time interval before repeat test to allow time for regression
what confirmatory tests can be used for FeLV?
immunoflourescent antibody
PCR
what sample can be used for an immunoflourescent antibody test for FeLV?
blood and bone marrow
what sample can be used for a PCR test for FeLV?
blood
bone marrow
any tissue sample
what does a immunoflourescent antibody test for FeLV look for?
FeLV antigens in blood cells which indicate marrow infection
what does a PCR test for FeLV look for?
proviral DNA
Viral RNA
why may a FeLV false negative occur?
can take up to 1 month for FeLV antigen to be detectable
what should be done if an FeLV test result is negative but exposure is suspected?
retest in 1-2 months
why is the FeLV diagnosis in kittens not complicated like the FIV diagnosis?
tests are looking for antigens not antibodies
maternal antibodies or vaccine antibodies cannot interfere with test
is there currently any medication which can clear FIV and FeLV virus from the body?
no
what are the main methods of treatment for FIV and FeLV?
supportive management and nursing care
what are the main nursing care points for FIV and FeLV patients?
ensure well hydrated adequate nutritional provision management of manifestations of disease antiviral drugs interferons
how can bacterial manifestations of FIV and FeLV be managed?
antibiotics
how can chronic gingivostomatosis manifestations of FIV and FeLV be managed?
dental hygiene
extractions
analgesia/anti-inflammatories
how can uveitis manifestations of FIV and FeLV be managed?
anti-inflammatories
atropine
what may antiviral drugs be useful for during supportive management of FIV/FeLV?
may help with gingivostomatosis or neurological signs in FIV cats
how should FIV/FeLV cats be managed at home?
indoor only
neutered
seperate + and - cats
no hunting or raw food
what should increase in frequency for FIV/FeLV cats?
heath checks
what should FIV/FeLV cats be vaccinated against?
core vaccinable diseases
what type of vaccines should be used for FIV/FeLV positive cats?
inactivated only
why should FIV/FeLV cats remain indoors?
prevent transmission
reduce exposure to opportunistic infections
how can FIV/FeLV viruses be removed from the environment?
1:32 bleach in water solution
fomite transmission in FeLV key - no shared equip
how can FIV be prevented?
vaccination
what are the risks associated with FIV vaccine?
adjvant in vaccine is linked to risk of sarcoma
vaccine is not fully protective
complicates interpretation of serology results
what cats in the UK are usually vaccinated against FIV?
only those at high risk - prolific fighters
what must be done before vaccinating against FIV?
test to ensure cat is seronegative
how can FeLV be prevented?
vaccine (non-core)
what does the FeLV vaccine do when used prophylactically?
offers protection from progressive infection
what cats should be vaccinated against FeLV?
outdoor cats
multi-cat environment (especially if FeLV + cat in household)
when should FeLV vaccines be started?
kitten vaccines
hen are repeat vaccines of FeLV needed?
q1-3 years depending on brand
what is the prognosis for sick positive FIV cats?
less than one year
what is the median length of survival post FIV diagnosis?
4-6 years
is there a significant difference between healthy positive vs. negative cats survival?
no
what leads to more rapid FIV deterioration?
feline AIDS in kittens and geriatric cats
what is the prognosis of FeLV regressive infection?
usually leads to FeLV associated disease within 3-5 years
survival time is less than half that of non-FeLV cats
once sick prognosis and quality of life is poor
describe a feline coronavirus (FCoV)
large
enveloped
RNA virus
why does the virulence of FCoV vary?
mistakes occur frequently during replication meaning that some are able to infect macrophages and others have no disease signs at all
what are the signs of a low virulence FCoV?
often no signs - GI infection
what are the signs of a medium virulence FCoV infection?
may see vomiting and diarrhoea
describe the effect of a high virulence FCoV infection
mutlisystemic effects - fatal
how is FCoV transmitted?
faecoorally
where is FCoV found?
everywhere within the environment
how prevalent is FCoV infection?
high - up to 100% of cats in multicat households will be infected with FCoV at some satge
how prevalent is FCoV related clinical disease?
very low - low virulent strain is common
what can FCoV mutate into?
feline infectious peritonitis
how is FCoV infection shed?
faecally
how will another cat pick up FCoV infection?
faeco-oral transmission
smelling faeces, contaminated fomites (shared litter trays)
where does FCoV replicate?
within the intestine
are there usually signs of FCoV infection?
frequently no signs, can be small intestinal diarrhoea
when is FCoV shed faecally?
1 week following infection
some cats are lifelong shedders
when can mutation of FCoV to FIPV occur?
any time after FCoV infection
often a number of months later
where does mutation from FCoV to FIP occur?
within the individual cat
is FIPV considered to be spread between cats?
no
why is FIPV not considered to be spread between cats?
as the mutation of FCoV to FIPV occurs in individual cats
how is FIPV systemically disseminated?
by its ability to replicate within macrophages and so be carried in the blood
in how many FCoV infected cats does FIPV occur?
5%
what are the 2 types of FIPV?
wet and dry
what does the type of FIPV depend on?
individuals immune response
which is the most common form of FIPV?
wet
what happens during wet FIPV?
inflammation around blood vessels causes them to become leaky leading to effusions
what happens during dry FIPV?
inflammation doesnt cause effusion, leads to formation of granulomas which prevent the organs from working properly
what is the outcome of FIPV?
invariably fatal
how many cases of FIP are wet?
up to 80%
what does wet FIP lead to the development of?
effusions and their associted clinical signs
what are the signs associated with abdominal effusion?
abdominal distention
what are the signs associated with pleural effusion?
tachypnoea
dyspnoea
what are the signs associated with pericardial effusion?
right sided heart failure if effusion is large enough
what signs will a wet FIP cat present with?
frequently jaundiced lethargy inappetance weight loss pyrexia
how does dry FIP cause organ dysfunction?
development of pyo/granulomatous lesions withn multiple organs leading to dysfunction and sometimes organomegaly
what is organomegaly?
increased size of organs
what areas of the body are affected by dry FIP?
lymph nodes brain eyes liver kidney
what are the main signs of dry FIP which is affecting the brain?
neurological signs including seizures
what are the main signs of dry FIP which is affecting the eyes?
uveitis
chorioretinitis
what are the main signs of dry FIP which is affecting the intestines?
focal granulomas
what are the main signs of dry FIP which is affecting the kidneys?
renomegaly
are effusions seen with dry FIP?
no - may develop with time leading to wet FIP
what are the main signs of dry FIP?
may be jaundiced lethargy inappetance weight loss pyrexia
of wet and dry FIP which is the more chronic disease?
dry
is there a specific test for FIP?
no
is there a test to distinguish between FCoV and FIP?
no as they are the same virus
what is the only testable difference between FCoV and FIP?
ability to infect macrophages
and so ability to cause multi-systemic disease
what is the signalment of FIP?
commonly under 1 but well recognised up to 3 years old
pure bred cats
multi-cat households
when is a second peak of FIP seen?
in geriatric cats
what may be seen in the history of FIP cats?
a recent stressor (e.g. rehoming, vaccination, neutering)
what is often found on examination of FIP cats?
weight loss poor condition often jaundiced \+/- effusions \+/- occular changes \+/- neurological signs \+/- palpably enlarged lymph nodes / liver / kidneys
what is seen on haematology assessment of FIP cats?
may be normal
no classic sign
often lymphopenia and non-regenerative anaemia
what are the typical serum biochemistry changes of a cat with FIP?
increased globulin
reduced albumin
increased bilirubin
increased alpha1-acid glycoprotein
what is the albumin:globulin ratio in FIP cats?
<0.4
what is increase in alpha1-acid glycoprotein associated with?
inflammatory conditions so not specific to FIP
what imaging may be used in patients with FIP?
abdominal ultrasound
thoracic ultrasound
CNS MRI if neuro signs
why should you keep scanning an FIP cat even if fluid isn’t seen?
as it may develop after fluid therapy which shouldn’t happen in a normal cat
what are you looking for on an abdominal ultrasound of an FIP cat?
abdominal effusion
lymphadenomegaly
various other organ changes
what are you looking for on a thoracic ultrasound of an FIP cat?
pleural effusion
pericardial effusion
what equipment is required for an abdominocentisis?
10 ml syringe
butterfly catheter
EDTA and serum tubes
what is the most useful test for FIP?
effusion analysis
why is there high levels of protein in exudate?
due to increased globulin levels
describe effusion exudate
thick
yellow
proteinaceous
what cells are often found in exudate of a FIP cat?
neutrophils and macrophages
what test can be used to check for presence of exudate (not FIP specific)?
Rivalta’s test
What are the 2 other effusion fluid tests that can be performed to diagnose FIP?
FCoV reverse transcriptase PCR
Innunocytochemistry
what is RT-PCR of effusion fluid from a FIP cat looking for?
FCoV nucleic acid in effusions
when may you get a false negative PCR for FCoV?
if no/small amount of FCoV in sample
how does immunocytochemistry of effusion fluid from a FIP cat work?
use of fluorescent labelled probes to demonstrate FCoV within macrophages (only seen with FIP)
what can be tested if the patient doesn’t have wet FIP and so there is no effusion fluid to use?
wait to see if effusion develops
histopathology of perivascular granulomatous /pyogranulomatous lesions in affected organs
immunohistochemistry to demonstrate FCoV in macrophages
what process is histopathology for FIP often used in?
post mortem diagnosis
is FCoV serology useful at all?
no
why is FCoV serology not at all useful?
only demonstrates FCoV exposure which is likely to have happened to every cat due to it’s prevalence in the environment
when do antibodies to FCoV / carrier status of FCoV occur?
healthy cats who are carrying FCoV who will never get FIP
cats with FIP
why can a negative FCoV serology result never be used to exclude FIP infection?
immune response may not have occurred at all
immune response is now reduced due to the progress of disease
is there treatment available for FIP?
currently uniformly fatal
what is management of FIP aimed at?
improving quality of life - palliation
when is euthanasia of FIP cases usually warranted?
within weeks of diagnosis
what drug can be used to palliate signs of FIP for a short period in mildly affected cases?
Prednisolone
why may dry FIP cases survive longer?
wet become hypovolaemic quickly due to effusions
what treatments are being trialed for FIP?
protease inhibitors
nucleoside analogues
what is the main role of the treatments that are currently being trialed for FIP?
interfere with replication of virus
what type of immunity is required for protection from FIP?
cell mediated immunity
what antibodies to FCoV are kittens born with?
maternally derived
when does kittens antibodies to FCoV wane?
after around 6 weeks when they will be infected by their mother / environment
is vaccination for FCoV currently advised?
no
via what route is the FCoV vaccine given?
intranasal
when is the FCoV vaccine licenced from?
16 weeks
why is systemic immunity to FCoV following vaccine not convincing?
replicates within the respiratory tract and doesn’t migrate
likely to be local immunity only
what happens if FIP develops following FCoV vaccine?
prior vaccine can exacerbate the clinical disease
why can prior FCoV vaccine exacerbate FIP clinical disease?
antibody related immune complexes are involved in pathogenesis of the pyo/granulomatous inflammatory reactions
is FIP considered infectious?
no
how long can FCoV survive in the environment?
a few days
how long can FCoV survive in faeces?
up to 7 weeks
what cleaning methods is FCoV susceptible to?
most disinfectants including bleach (1:32)
who should be informed if a cat dies of FIP?
the breeder
how long should a single cat household wait before acquiring another cat if the previous one has died from FIP?
2 months to enable household FCoV to die
how should the post FIP infection period be managed in a multi-cat household?
take steps to reduce stress/overcrowding
ensure cleanliness
consider that other cats are likely already FCoV exposed
where should queens kitten to reduce FCoV risk?
away from other cats
what are some key breeder considerations to prevent FCoV becoming FIP?
queens should kitten away from other cats
consider early weaning
avoid repeat matings that have resulted in multiple FIP kittens
quarantine household and avoid breeding 6 months following FIP case
how can FIP be prevented?
minimise stress
aim for single or small group cat households
avoid overcrowding
ensure good hygiene - FCoV spread faecally
how can stress be minimised to reduce risk of FIP?
don’t re-home kittens too early
seperate major events over a number of weeks (e.g. rehoming, vaccination and neutering)
is it possible to have a FCoV free household?
almost impossible
how can you increase the likelihood of FCoV free household?
maintain single/small group closed population
test any new additions (PCR) and only introduce negative cats
evaluate FCoV antibodies and FCoV shedding to seperate + and - cats
what drug has been shown to reduce faecal shedding of FCoV?
Oral Mutian X
what is Toxoplasma gondii a type of?
protozoal parasite
what is the definitive host of Toxoplasma gondii?
cats
what are the intermediate hosts of Toxoplasma gondii?
most warm blooded vertebrates (including cats and humans - zoonotic)
what is the definitive host of a parasite?
the host in which parasitic sexual maturity and reproduction occurs
what is the intermediate host of a parasite?
the host in which one (or more) stage(s) of parasitic development occurs
what is the transport host of a parasite?
a host in which the parasite may survive but no parasitic development occurs - may be a vector / vehicle for transmission to other hosts
how many people in the UK are infected with Toxoplasma?
up to 1/3 of people
do all people infected with Toxoplasma develop disease?
no - only a minority
how are humans infected with Toxoplasma?
ingestion of raw meat or contact with faeces which contain it
what leads to sporulation of Toxoplasma oocysts?
appropriate conditions e.g. oxygen level, temperature, humidity
what happens during sporulation of Toxoplasma oocysts?
development of sporozoites within oocysts
what is the name of the non infectious T.gondii oocyst?
unsporulated form
what is the name of the infectious form of T.gondii oocyst?
sporulated form
what is found in the sporulated oocyte of T.gondii?
sporozoites
what is schizogony?
asexual reproduction which produces merozoites
what is produced by schizogony of T.gondii?
merozoites
what will merozoites of T.gondii transform into?
either macrogamete (female) or microgamete (male)
how is an T.gondii oocyst formed from micro and macro gametes?
through sexual reproduction penetration of macrogamete by microgamete
when are tachyzoites formed?
during rapidly dividing stage - active infection
when are bradyzoites formed?
slowly dividing / tissue cyst stage (latent infection)
what happens if bradyzoites are ingested by cats?
transforms to merozoites in the GI tract
when do T.gondii oocycts become infectious to the intermediate host?
following sporulation
what is the only definitive host of T.gondii?
cats
how are cats typically infected with T.gondii?
ingestion of bradyzoites in prey tissues or raw meat
where are merozoites formed in the cat?
intestinal epithelial cells
how is the zygote shed from the host cat?
faecally as an unsporulated oocyst
how long are oocysts shed in the definitive hosts faeces?
up to 3 weeks post ingestion
how does T.gondii enter the intermediate host?
sporulated oocyst or bradyzoite ingestion (raw meat)
how does systemic spread of T.gondii occur in the intermediate host?
sporozoites released in intestinal tract which leads to systemic spread by penetration of blood and lymph
what types of mammalian cells can T.gondii enter/infect?
most types of cells
what causes clinical T.gondii disease in the intermediate host?
rapid asexual reproduction (tachyzoites) within cells which leads to pathology in infected organ/cell
how long can production of host bradyzoites persist for?
indefinitely
when may production of tissue bradyozoites be reactivated?
at times of stress, pregnancy, immunosuppression
what are the particular sites of T.gondii replication?
CNS, skeletal muscle, organs
what can infection of mammalian cells with T.gondii lead to?
cell death
what antibodies are produced in response to acute infection with T.gondii?
IgM
what antibodies are produced in response to convalescence from infection with T.gondii?
IgG
what do antibodies to T.gondii correlate with?
infection status rather than clinical disease
how is clinical T.gondii disease prevented in most intermediate hosts?
most will mount a successful immune response which prevents ongoing T. gondii replication and so clinical disease
what can immunosuppression of a T. gondii intermediate host at any time lead to?
reactivation of latent disease
why is there geographical variation in seroprevalence of T. gondii?
due to the difference in conditions - some of which may not be optimal for oocyst sporulation
how may sick cats are seropositive for T.gondii?
1/3
what are the main risk factors for T.gondii exposure?
raw diet
outdoor lifestyle
hunting
age
why does age increase risk for T.gondii exposure?
more time to be exposed!
what are the clinical signs of T. gondii?
non specific - lethragy anorexia occular neurological hepatic pancreatic pulmonary
are GI signs often seen in T. gondii infection?
no - even though it is a GI disease
what are the occular sign of T. gondii?
uveitis
chorioretinitis
what are the neurological signs of T. gondii?
CNS
neuromuscular disease
altered behaviour (e.g. rats loose aversion to cats)
what are the pulmonary signs of T. gondii?
dyspnoea
is there specific pathognomic examination / routine finding associated with T. gondii?
no
what may be indicated by serum biochemistry of suspected T. gondii patient?
organ involvement (e.g. altered hepatic/muscle enzymes)
what may be revealed by thoracic radiographs of a patient with T. gondii?
pulmonary parenchymal disease
are faecal oocysts helpful when diagnosing T. gondii?
no
why are faecal oocysts not helpful when diagnosing T.gondii?
indicates that the cat has been a definitive host recently due to short period of shedding but doesn’t indicate clinical disease
how can t. gondii be diagnosed?
looking for immune response to the organism
looking for organism itself
what antibodies will show response to T. gondii?
IgM
IgG
what level of IgM will indicate clinical T. gondii disease?
> 1:64
what level of IgG will indicate T. gondii clinical disease?
4 fold increase in IgG
when is IgG usually detactable?
3-4 weeks post T. gondii infection
how long may levels of IgG remain elevated for following T. gondii infection?
commonly remain elevated for years
when is IgM usually detectable following T. gondii infection?
2-4 weeks
when has IgM usually returned to normal after T. gondii infection?
by 16 weeks
how can the T. gondii organism be found?
cytology
histology
where may cytology / histology samples be taken from to test for T. gondii?
fluid analysis (CSF, bronchoalveolar lavage, effusions) FNA or biopsy (e.g. liver)
what is indicated if T. gondii is found in cytology / histology?
diagnostic for clinical disease
what is indicated if T. gondii is not found in cytology / histology?
doesn’t exclude the disease
what may be performed on sample if T. gondii is found in cytology / histology?
PCR specific to T. gondii as it appears microscopically identical to N. caninum
what is the most common treatment for t. gondii?
Clindamycin
how long is Clindamycin given for to treat T. gondii?
4 weeks
what is a consideration when giving Clindamycin to treat T. gondii?
oesophageal strictures are a risk - ensure it is washed down or given with food
what supportive management of T. gondii is needed?
uveitis therapies
systemic prednisolone (anti-inflammatory)
nutritional / fluid support / anti-emetics
what uveitis therapies may be given to T. gondii patients?
analgesia
anti-inflammatories
is elimination of T. gondii possible?
no - treatment only suppresses replication and improves clinical signs
what makes prognosis of T. gondii poor?
CNS, hepatic or pulmonary involvement
concurrent disease leading to immunosuppression or actual immunosuppression
what may survivors of T. gondii be left with?
may recover fully or be left with residual dysfunction due to affected organs
what is the most common route that humans are infected with T. gondii?
ingestion of tissue cysts from raw meat ingestion
how can lambing pose a T. gondii infection risk?
causes abortion in sheep
contact with infected sheep placentae / lambing discharges
can T. gondii survive in the environment?
yes and resistant to most disinfectants
when can T. gondii risk foetal complications (inc. still birth)?
if initial infection occurs during preganacy
how can regular cleaning of litter tray avoid T. gondii infection?
takes 1-5 days for sporulation to occur so if faeces are removed regularly there should be no infection risk
how are haemotropic mycoplasmas commonly identified clinically?
feline erythrocytic infections
what are the 3 types of haemotropic mycoplasmas?
Mycoplasma haemofelis
Candidatus Mycoplasma haemominutum
Candidatus Mycoplasma turicensis
what is the pathogenic type of haemotropic mycoplasma?
Mycoplasma haemofelis
can all 3 species of haemotropic mycoplasmas be present in cats?
yes - separately and concurrently
what are the modes of transmission of haemoplasmas?
remains elusive - suggested routes: iatrogenic various arthropod vectors (e.g. fleas) bite / fight wounds vertical transmission
what is the main iatrogenic method of haemoplasma transmission?
blood transfusions
what are the risk factors for haemoplasmosis?
outdoor access
male
non-pedigree
what are the additional risk factors for M. haemofelis disease?
young
FIV and/or FeLV positive
what is the least prevalent but most pathogenic of the 3 feline mycoplasmas?
Mycoplasma haemofelis
where does M. haemofelis attach?
cell surface of erythrocytes
what does M. haemofelis lead to?
haemolytic anaemia
what are the clinical signs of M. haemofelis related to?
anaemia
what is the incubation period of M. haemofelis?
2 days - 1 month
how long does acute disease (haemolytic anaemia) last in M. haemofelis?
2-4 weeks
why is there cyclical pathogen presence with (sometimes cyclical) anaemia in M. haemofelis infection?
rapid replication of pathogen and then removal by the immune system
how may the presence of M. haemofelis vary between individuals?
severity and duration - can cause sudden collapse and anaemia in some
how may M. haemofelis be overcome?
treatment or natural recovery in some cases
what happens during the recovery phase of M. haemofelis?
complete removal or sub-clinical clearance of organism from blood
what do of M. haemofelis signs depend on?
severity of diesase
what are the clinical signs of M. haemofelis?
non-specific - weak, lethargic, inappetant pallor (pale) tachypnoea icterus (uncommon) tachycardia heart murmurs splenomegaly pyrexia pica
what can cause icterus in the M. haemofelis patient?
due to haemolysis
what would be found on haematology tests of a patient with M. haemofelis?
regenerative or pre-regenerative anaemia
reticulocytes
agglutination
why does agglutination of RBC occur in haematology of M. haemofelis patients?
antibodies attach to bacteria on the RBC surface which causes them to clump together
is blood smear examination reliable in M. haemofelis diagnosis?
no
why is blood smear not reliable in M. haemofelis diagnosis?
cyclical nature of infection means haemoplasmas aren’t always visible on RBC
haemoplasmas may fall off ex vivo RBC following collection
other features cannot be reliably differentiated from haemoplasmas (e.g. Howell-Jolly bodies)
what is the best method of diagnosing haemoplasmas?
PCR
what sample is used for PCR to test for haemoplasmas?
blood sample (EDTA)
what is the first line of treatment of haemoplasmas?
Doxycycline
how long does Doxycycline treatment for M. haemofelis last for?
2 weeks
what is gained through Doxycycline treatment of M. haemofelis?
clinical remission but may not eradicate organism
what other treatment may be offered for M. haemofelis?
blood transfusions
prednisolone
what is the role of prednisolone in treatment of M. haemofelis?
steroids to treat IMHA
when is response to M. haemofelis treatment usually seen?
within a few days
are haemoplasmas seen in dogs?
of rare clinical significance
may be carried
what is the canine specific haemoplasma?
Haemoplasma spp.
under what scenario can haemoplasmas cause haemolytic anaemia in dogs?
splenectomised patients
immunocompromise
concurrent disease
