Viral disease of the lymphoid system Flashcards
Define immunocompromised
any aspect of host defences is deficient
define immunosuppressed
immune defences are specifically impaired
define immunodeficient
bodys immune response is compromised or absent
List 4 ways in which viruses can enter a cell
Utilisation of naturally occurring and useful receptors on the cell surface.
endocytosis
direct injection (bacteriophages)
fusion of the envelope (some enveloped viruses)
How does canine distemper virus cause disease
infects a number of cells but causes destruction of lymphocytes- so immune system becomes badly infected
How is canine distemper virus transmitted
oro-nasal infection- inhalation of aerosol
then spreads to other haemopoitetic organs
How does canine parvovirus 2 cause disease
tropism for fast dividing cells (GI tract crypts, bone marrow, lymphoid tissue)-
destruction of white blood cells precursors within bone marrow- so will have very low WBC
How does Feline Panleukopenia Virus cause disease
tropism for fast dividing cells (GI tract crypts, bone marrow, lymphoid tissue)-
destruction of white blood cells precursors within bone marrow- so will have very low WBC count
what are the different sub-types of Feline Leukaemia Virus
4 subtypes
A, B, C and T – all closely related antigenically
how is Feline Leukaemia Virus (FeLV) transmitted
transmitted through mutual grooming and rarely through bites
doesn’t last long in the environment
List 3 risk factors for Feline Leukaemia Virus (FeLV)
young age
increased population density
poor hygiene
what can happen when cat gets infected with Feline Leukaemia Virus (FeLV)
Abortive infection- cat eliminates the virus
OR
progressive infection
OR
Regressive infection
describe what happens in regressive Feline Leukaemia Virus (FeLV) infection
virus replication controlled prior to or shortly after bone marrow infection
So cat aint infective to others but if becomes immunocompromised virus could reactivate and cat can become infective
describe what happens in progressive Feline Leukaemia Virus (FeLV) infection
persistent vireamia and high risk or FeLV-related disease
T/F regressive Feline Leukaemia Virus (FeLV) become progressive
True
the cat wont become ill but will see antigens in the cats blood
What would you see on FeLV point of care Ag screening in abortive infection
Ag-
PCR -
What would you see on FeLV point of care Ag screening in progressive infection
Ag +
increased PCR +
reduced lifespan
What would you see on FeLV point of care Ag screening in regressive infection
Ag-
decreased PCR+
OR
Ag+
PCR-
How is Feline Immunodeficiency Virus (FIV) transmitted
via deep wounds inoculation with saliva- related to aggressive behaviour
kittens born to persistently infected queens- rarely infected but antibodies may be present
How does Feline Immunodeficiency Virus (FIV) cause immunodeficiency
Infects CD4+ T lymphocytes ( T helper cells) which are crucial for humoral and cell-medicated immunity.
what cats are at risk of Feline Immunodeficiency Virus (FIV)
Promiscous (unneutered)
old
male
stray (free-ranging)
List the clinical signs of acute phase Feline Immunodeficiency Virus (FIV)
transient mild fever
anorexia
lymphadenopathy
List what can happen in the clinical phase of Feline Immunodeficiency Virus (FIV)
functional immunodeficiency may develop in some cats (doesn’t occur in all cats)
increased risk of :
- secondary infections
- immune-mediated disease
- neoplasia
If you see Gingivostomatitis what could it suggest that the cat has
Feline Immunodeficiency Virus (FIV)
what aged cats does Feline Infectious Peritonitis Virus (FIP) tend to affect
weaning age
>10 yrs old
List the 2 forms of Feline Infectious Peritonitis Virus (FIP)
effusive (wet FIP)
non-effusive (dry FIP)
where do you tend to see problems with effusive FIP
any body cavity including pleural and pericardial cavities, as well as abdominal cavity.
where do you tend to see non-effusive form of FIP
usually ocular and neurological presentations.
what causes the effusion in effusive FIP
due to multisystemic inflammatory vasculitis (pyogranulomatous vasculitis)
what is antibody-dependent enhancement
potential for exacerbation of the disease by pre-existing antibodies
important in FIP
Can you cure FIV
No
how long can it take for FIV disease to cause disease
weeks to years
why should shelters test for FeLV and FIV
as they can spread fast and cause lifelong severe disease
