Remember me! Flashcards
Name three erosive diseases of cattle
Bovine virus diarrhoea virus
Malignant catarrhal fever
Rinderpest
Describe the pathology of malignant catarrhal fever
- generalised disease, invariably fatal
- erosive lesions of GIT
- respiratory lesions
- mucopurulent naso-occular discharge
- lymphoproliferation and lymphocyte infiltration
- vasculitis
- corneal opacity
- neurological sins
Describe the epidemiology of malignant catarrhal fever
Carried asymptomatically by wildebeast and sheep
Sporadic transmission to cattle, deer via contact or infected pastures
Describe the diagnosis of malignant catarrhal fever
PCR
Describe the control of malignant catarrhal fever
No vaccine available
Control contact with wildbeast/sheep/infected pasture?
Describe the pathology of virus diarrhoea syndrome
Mild GIT erosions
diarrhoea
immunosuppression
respiratory disease
May be mild or subclinical
Describe the pathology of reproductive syndrome caused by bovine virus diarrhoea virus
Reproductive problems in naive dams infected with cytopathic or non-pathogenic strains
embryonic death, abortion, calves with cerebellar hypoplasia
+/- Bovine virus diarrhoea
Describe the pathology of mucosal disease
Severe erosion of the GIT and digits
Depression, fever, profuse diarrhoea
Describe the pathogenesis of bovine virus diarrhoea virus when infecting foetuses at varying stages of gestation
If infected at (day) of gestation
Day 0-40: embryonic loss
Day 40-120: Persistently infected, immunotolerent calf (Ag +ve, AB -ve) -> Mucosal disease 6-18mo
Day 90- 160: Congenital abnormalities (Ag, AB variable)
Day 140-280: clinically normal, or small weak calf (Ag -ve, AB +ve)
Describe the diagnosis of Bovine virus diarrhoea virus
Serological or molecular testing
antigen tests / PCR
skin (e.g ear notch) or blood samples
Mucosal disease: Ag +ve, Ab -ve
Which family does malignant catarrhal fever belong to?
Herpesvirus
Which family does bovine virus diarrhoea virus belong to?
Flavivirus (Pestivirus)
Which family does rinderpest belong to?
Paramyxovirus
Describe the epidemiology of rinderpest
severe disease, high incidence, high case fatality in cattle
Mild disease in cattle, buffalo, game animals, sheep, goats
Describe the pathology of rinderpest
inflammation, haemorrhage, erosions, necorsis of digestive mucosal membranes, diarrhoea, death
List the vesicular diseases of pigs
Foot and mouth disease
Swine vesicular disease
Vesicular exanthema
Vesicular stomatitis
What family does vesicular stomiatitis belong to?
Rhabdovirus
Describe the pathology of vesicular stomatitis virus
Similar to FMD: causes vescicular lesions on mouth, snout, feet; rupture to leave ulcerative areas
Describe the host range of vesicular stomatitis
pigs, horses, cattle, zoonotic
Describe the transmission of vesicular stomatitis virus
Arthropod vectors (probably mechanical)
Write brief notes on vesicular exanthema
Disease seen in pigs in USA between 1932-1956 (now eradicted)
Vesicular disease, similar to FMD
Same as San Miguel sea lion virus
Probably resulted from feeding pigs marine mammals
Which family does vesicular exanthema belong to?
Calcivirus
Which family does foot and mouth disease belong to?
Picornavirus (Apthovirus)
Describe the host range of foot and mouth disease
Cloven-hoofed animals including cattle, deer, sheep, goats, pigs
rarely, humans
Describe pathology of foot and mouth disease
Cows, pigs: fever, depression, loss of production
vesicles on tongue, gums, snout, feet, teats
Sheep and goats with mild or subclincal infections
Discuss the economic factors involved in foot and mouth disease
Loss of production, but less significant in endemic areas
Significant impacts on international trade
Discuss transmission of foot and mouth disease
- short incubation period
- high concentrations of virus shed in aerosols, esp. pigs; can be transmitted long distances on wind;
- infection via respiratory route
- virus can be shed before clinical signs observed
- small infectious dose
Is foot and mouth disease a good candidate for eradication? Why/why not?
- large amounts of virus shed into environment, can travel long distances on wind
- can be shed before clinical signs observed
- rapid replication cycle (short incubation period)
- small infective dose
- many serotypes & subtypes, short-lived immunity -> vaccination problems
- extremely resistant in environment at neutral pH (resistant to detergents and dessication)
Discuss the serotypes of foot and mouth disease
- 7 serotypes: A, O, C, SAT1, SAT2, SAT3, Asia1
- Many subtypes per serotype (> 80 total)
- Immunity to one serotype does not protect against others
- Immunity to one subtype may or may not protect against others
- Need correct subtype in inactivated vaccines to protect against local strains
- short-lived immunity, boosters required /6m
Describe the control of foot and mouth disease in exotic countries
- strict control for importation of animal products/swill feeding to pigs
- strict quarantine measures
- slaughter of affected animals
- +/- ring vaccination
- alert authorities if suspect vesicular disease
- monitoring/surveillence
Describe the host range of swine vesicular disease
Pigs only
Describe the pathology of swine vesicular disease
foot lesions; snout lesions uncommon
Which family does swine vesicular disease belong to?
Picornavirus
Are herpesviruses good candidates for eradication? Why/why not?
Yes
- can screen population using antibody detection tests (relatively cheap)
- remove carriers (AB+)
- fragile virus with no long-term environmental reservoirs
Which family does feline rhinotracheitis virus belong to?
Herpeviridae
(Feline herpesvirus 1)
Describe the pathology of feline rhinotracheitis virus
upper respiratory tract disease
responsible for 40% of cat flu
rhinitis
oculo-nasal discharge
inappetance
confjunctivitis
keratatis
+/- secondary bacterial pneumonia
generalised disease in neonates
Describe the control of feline rhinotracheitis virus
Live attenuated vaccine
not 100% protective
Describe the treatment of feline rhinotracheitis virus
management of clincal signs
reduce stress
prevent/treat secondary bacterial infections
nucleotide analogues (famcyclovir)
Compare and contrast vesicular diseases
EDIT: SVD via oral route or broken skin
direct contact or ingestion (e.g. of contaminated pork products)
Describe the pathology of feline calcivirus
Upper respiratory tract infection (rhinitis, fever, conjunctivitis)
ulcerative glossitis
Sometimes pneumonia and death, esp. kittens
Some virulent strains cause systemic infections with facial and limb oedema, alopecia, and ulceration of feet (rare)
List the pathogens involved in cat flu
Feline calcivirus (40%)
Feline herpesvirus (40%)
Chlamydia (20%)
Is feline calcivirus a good candidate for eradication? Why/why not?
No
- Many serotypes, leading to vaccination failure
- Shed from oropharynx for >1y after recovery (carrier animals)
- Resistant in environment
Describe the control of feline calicvirus
Attenuated vaccines available, but vaccination failures not uncommon (many serotypes)
Describe the pathology of bovine coronavirus
Neonatal diarrhoea < 3w.o
Winter dysentery and respiratory disease in cows
Describe the control of bovine coronavirus
Neonatal calves most at risk -> vaccinate dams, ensure sufficient colostrum intake
List two viruses that might cause diarrhoea in calves
Bovine virus diarrhoea virus
Bovine coronavirus
Name the three genera of Reoviruses
Orthoreovirus
Orbivirus
Rotavirus
What family does bluetongue belong to?
Reovirus (Orbivirus)
Describe transmission of bluetongue
arbovirus (biological transmission by Culicoides)
Multifactorial: age, stress, rough terrain; sheep vs cattle proportions (preferred host = cattle)
Non-contagious between sheep; severity depends on strain of virus and breed of sheep
Cattle important amplifying hosts (viremia ~4 months)
Describe the pathology of bluetongue in sheep
Can be prolonged, progressive disease
Variability in clinical signs
- catarrhal (mm) inflammation of digestive and respiratory tracts with erosions)
- fever, swollen lymph nodes
- mucopurulent nasal discharge; swelling of nose and mouth
- damage to small blood vessels
- odema, cyanosis, haemorrhage
- distension of tongue
- coronitis (hyperaemia, red->purple swelling of coronary band)
- muscle degeneration, loss of condition, emaciation
- congenital abnormalities
- Postmortem: yellow/gelatinous/haemorrhagic SQ, thoracic, abdominal oedema
-
Describe the pathology of bluetongue in cattle
Usually asymptomatic or mild disease
congenital defects from in utero infection
Describe some of the major attributes of bluetongue
arbovirus
>20 serotypes, not cross protective
11 strains present in Aus; mostly low virulence; this may be changed with changing climactic factors and spread of cattle into sheep areas
Discuss the control of bluetongue
Live attenuated or killed vaccines used in some countries (need to know local serotype of prevelance)
Attenuated viruses can cause congenital defects
Concerns about genetic reassortment of vaccine and field strains (killed vaccines may be safer, but less effective)
Describe the pathology of Newcastle disease
severe, generalised disease (sometimes confused with fowl plague)
in chickens, turkeys, pigeons, parrots, +/- other avians
respiratory, intestinal, nervous signs
haemorrhagic enteritis and tracheitis, encephalitis, hepatic necrosis and haemorrhage
What family does Newcastle disease belong to?
Paramyxovirus (Morbillivirus)
Describe the subcategories of newcastle disease
Only one serotype, BUT
Lentogenic: can only replicate in epithelial cell, no disease
Mesogenic: moderate disease
Velogenic: can replicate in many cell types - severe disease, high case fatality, highly virulent. Varies by 2 amino acids from lentogenic strain
Viscerotropic: prediliction for GIT
Pneumotropic: prediliction for resp. tract
Describe control of Newcastle disease
In endemic countries, vaccination with lentogenic strain (selected for heat stability)
In exotic locations, slaughter
Describe control of Newcastle disease
In endemic countries, vaccination with lentogenic strain (selected for heat stability)
In exotic locations, slaughter
Describe the subcategories of newcastle disease
Only one serotype, BUT
Lentogenic: can only replicate in epithelial cell, no disease
Mesogenic: moderate disease
Velogenic: can replicate in many cell types - severe disease, high case fatality, highly virulent. Varies by 2 amino acids from lentogenic strain
Viscerotropic: prediliction for GIT
Pneumotropic: prediliction for resp. tract
What family does Newcastle disease belong to?
Paramyxovirus (Morbillivirus)
Describe the pathology of Newcastle disease
severe, generalised disease (sometimes confused with fowl plague)
in chickens, turkeys, pigeons, parrots, +/- other avians
respiratory, intestinal, nervous signs
haemorrhagic enteritis and tracheitis, encephalitis, hepatic necrosis and haemorrhage
Describe the pathology of Fowl Plague
respiratory distress, cyanosis, nervous signs, diarrhoea, haemorrhage, rapid death
Name two diseases that can cause systemic disease and high mortality in birds
Fowl plague
Newcastle disease
List two diseases that could cause upper respiratory tract disease in horses
Equine rhinopneumatitis virus (EHV4)
Equine influenza (H7N7, H3N8)
List two diseases that can cause immunosuppression in cats
Feline leukaemia virus (oncovirus)
Feline immunodeficiency virus (lentivirus)
Which family does feline leukaemia virus belong to?
Retrovirus (oncovirus)
Discuss the prognosis of feline leukaemia virus
Depends on age and dose
Older cats: usually clear infection (immune response)
Young cats: persistent viremea, development of clinical signs, Px 2-3 years
Discuss the pathology of feline leukaemia virus
Older cats: clinically unaffected
Persistently viremic (esp young) cats: (FeLV-A + …)
- *FeLV-B**
- lymphoid and myeloid leukaemia
- lymphosarcoma
- *FeLV-C**
- bone marrow aplasia and anaemia
- *FeLV-T**
- immunosuppression
less commonly,
- reproductive failure
- glomerulonephritis
- osteosclerosis (abnormal hardening of bone)
Discuss the transmission of feline leukaemia virus
Shed in saliva and other excretions/secretions
Infection by prolonged close contact (e.g. sharing bowls, mutual grooming), via ingestion
Prevalence highest in multi-cat households and catteries
Describe diagnosis of feline leukaemia virus
Detection of FeLV antigen
Immunofluoresence, ELISA, rapid antigen detection tests
Describe control of feline leukaemia virus
Recombinant vaccine
Cats should be tested to ensure antibody-negative prior to vaccination
Test & remove effective in catteries
Describe the pathology of feline immunodeficiency virus
immunosuppression, opportunisitic infections
anaemia
lymphadenopathy
lethargy
febrile episdes
Describe the prevalence of feline immunodeficiency virus
transmitted via biting/fighting
Describe control of feline immunodeficiency virus
Killed vaccine
Keeping cats indoors
Describe diagnosis of feline immunodeficiency virus
detection of antibodies in serum
vaccine causes AB+ response, PCR for detection of pro-virus-DNA in blood samples now available
Describe the prognosis of feline immunodeficiency virus
Many cats live long lives
Only a small percentage develop AIDS (poor prognosis)
List viruses that are transmitted mechanically by arthropods
Myxoma
Fowlpox
Equine infectious anaemia
List arboviruses
Togaviruses: Eastern, western, venezualan equine encephalitis
Flaviruses: Japanese B encephalitis, Murray Valley encephalitis, Dengue, West Nile virus, West-Nile Kunjin virus
Asfarvirus: African swine fever virus
Rhabdovirus: Bovine ephemeral fever
