Infectious diseases of cats Flashcards
Main two viruses in cat flu
20% Feline herpes virus 1
80% Feline calicivirus
(+ influenza involved to some extent)
FHV-1 characteristics
Enveloped so easily inactivated
Establishes latent infection in trigeminal ganglion
dsDNA
Disease = anorexia, pyrexia, sneezing, nasal/ocular discharge
– Can get dermatological FHV from nasal secretion onto face
Treating FHV-1 drug
Famciclovir (= prodrug) for inhibiting viral DNA polymerase
Can also use aciclovir
Feline calicivirus characteristics
Non-enveloped so stable in environment
ssRNA
ANTIGENICALLY DIVERSE: lots of strains
Can get carriers via oropharyngeal persistent infection
Signs: URT signs + erosive lesions of tongue, nose and lips
+ in rare cases can get systemic disease
Drugs for feline calicivirus
NONE just supportive care
Do cat flu vaccines protect against disease
No - will just reduce severity
+ other viruses can cause this; we just vaccinate against main two
Chlamydia felis presentation and treatment
Conjunctivitis
= classic inflammatory reaction
Treat with doxycycline
Bordetella bronchiseptica in cats
Common in shelters
Causes sneezing, can get pneumonia (NB: cough uncommon)
= zoonosis
Histopath of parvovirus
Gross: haemorrhagic enteric lesions, loss of villus pile
Histopath: villus collapse (no replacement from crypt)
Dilated crypts, epithelial cells flatten
LNs show massive lymphocyte depletion due to lytic infection by virus
Characteristics of parvovirus
ssDNA non-enveloped virus so survives in environment well
Spreads via faeco-oral route
- Enters via oropharyngeal lymphoid tissue then get viraemia
Signs of parvovirus infection
Depression, pyrexia, hypothermia
+ diagnosis: on bloods so leukopenia, faecal ELISA/PCR
WHich virus causes FIP
coronavirus; mutated form which can infect macrophages to cause pyogranulomatous vasculitis
Dry vs wet FIP
Dry FIP: get moderate cell mediated response –> pyogranulomatous inflammation
Wet FIP: no cell mediated response; get high protein exudates in thorax/adbomen
There is progression from dry to wet
Effusion characteristics in wet FIP
High protein >35g/L and cell count less than 5000cells/ml
Typical cats getting FIP
Young pedigree cats from multi-cat househholds
What antigen are we detecting in blood in feline leukaemia virus test
p27
What capsid protein is used as part of FeLV vaccine
gp70
Possible outcomes of infection with FeLV
Abortive infection = cleared
Regressive infection= latency
Progressive infection = persistent viraemia; high fatality and mainly seen in YOUNG animals
Age = key determinant
What issue does viral envelope peptide p15E cause in feline leukaemia virus
immunosuppression via altering B and T cell function
Types of neoplasia caused by FeLV
Lymphoma
Leukaemia
Fibrosarcomas
How goodis the ELISA for FeLV
Sensitive: low false negative rate
But can get false +ves so need to confirm with virus isolation or immunofluorescence
How does FIV work
Infection via biting; then viraemia, then infects CD4+ T cells so get depresion –> immunodeficiency
Diagnosis of FIV infection
Via antibody detection to the p24 or gp41 proteins
risk of false +ve
Also risk of false negative because immune system so weak that antibody level not detectable
Cause of feline infectious anaemia
mycoplasma haemofelis
Typical cat with FIA
male, freeroaming, non-pedigree
Type of anaemia with FIA
= antibody-mediated haemolysis
Regenerative
Corresponds with cycles of parasitaemia at 6 day intervals
Treatment for FIA
Doxocycline for 6 weeks
Main cause of cat scratch disease
Bartonella henselae
What type of disease is cat scratch disease
infectious vasculoproliferative disease
What disease does mycoplasma lepraemurium cause
Feline leprosy
Which species can cause tuberculosis in cats
M bovis (from humans)
M microti (from voles)
seen in siamese + raw feeding association
Kitten vaccines
at 9 and 12 weeks old
With parvovirus, calicivirus and herpesviruses
Coronavirus characteristics
large enveloped ssRNA virus
Feline leukaemia virus type
Enveloped RNA retrovirus
ssRNA
FIV virus type
Retrovirus of family lentivirus
What strain does the FCV vaccine usually use
F9
After which vaccine might we see transient polyarthritis as a side effect
FCV
Pathology of feline calicivirus
In lungs get infection and necrosis of type 1 epithelial cells
Compensatory proliferation of type 2 cells which are more cuboidal and mipair exchange
+ if there is pneumonitis: see thickening of the alveolar septi
What drug is generally good for treating URT infections in cats
Tetracyclines
Which antibiotic do we avoid using to treat bordetella bronchiseptica due to resistance
Trimethoprim or ampicillin
(instead do for doxycylcine; could use amoxycillin/clav acid)
Effect of vaccination of ability to get latent carriers of cat flu viruses
DOESN’T STOP THIS
What tissues does parvovirus like to infect
Those with high mitotic rate i.e crypt epithelial cells, lymphoid tissue and BM, placental/fetal tissues esp cerebellum, myocardium
What can infection with parvovirus in utero lead to
If in first 1/3 gestation: fetal resorption
Middle-end gestation: cerebellar hypoplasia of neonate
What blood results suggests parvovirus infection and what suggests recovery from this
Initially get panleucopenia (decrease in number of all white blood cells)
> Then development of neutrophilia with left shift suggests recovery
Factors which determine whether cat exposed to feline coronavirus will develop FIP
Strain
Dose; higher dose gives higher FIP risk
Stress; cats developing FIP have history of stress in months before
Genetic susceptibility
What proportion of cats infected with FeCoV will go on to develop FIP
10%
Haematology signs of a cat with FIP
Hyperglobulinaemia (albumin:globulin ratio of <0.4 i.e 0.4:1)
Lymphopenia
More likely to find non-regenerative anaemia with dry FIP
Palliative treatment for FIP
Prednisolone; to modulate immune response
What molecule on FeLV determines subgroup and mediates attachment to receptors on cells
gp70
Subgroups = A, B, C
What antigen do we aim to raise antibodies against with vaccination for FeLV
gp70
FIV test aims to detect
p24 capsid protein (core)
Or gp41
Via antibody
What should we do if we get a positive in house FIV result
Confirm it with westerm blot or fluorescence antibody testing
Where do cats get tuberculosis mycobacteria from
M bovis from humans
M microti from voles
(NB: resistant to M tuberculosis)
What would muliple nodules on the head/limbs of a cat suggest
Infection with M lepraemurium from rodents
= feline leprosy
