Myxomatosis & Fowlpox Virus Flashcards
Myxomatosis in general
wild & domestic rabbits
presence of oedemic swelling or firm tumors on head
(rarely resp symptoms)
myxoma meaning in greek
muxa = mucous
oma= tumor
tumour of connective tissue embedded in mucous
Myxomatosis occurence
australia, europe, USA, central + south america
Myxomatosis causative agent
Myxoam virus
Myxoma virus general aspect
- heat sensitive
- in scabs, is infective for months
which hosts has the moste severe CS of Myxomatosis
Wild & domestic rabbit
Myxomatosis transmission
insects, mosquitoes (for wks)
fleas (in winter for mnths)
direct contact (breeding)
Myxomatosis forms
typical/nodular: oedemic tumors predilection sites
atypical/amyxomatous: resp signs
Myxomatosis pathogenesis
Vector → skin: primary replication → hydropic degeneration of the epithelial cells,
vesicles filled with serous fluid → skin necrosis
→ viraemia → damage of blood vessels → serous infitration of the corium, tumour-like myxoma cell proliferation and serous infiltration→ moist nodules in the skin
Myxomatosis incubation time
7-14 dys
Myxomatosis typical form CS
moist nodules on: eye, lips, nose, anus, etc
“lionhead”
blepharoconjunctivitis, rhinitis
100% mortality
Myxomatosis CS of Nodular form caused by viral strains with lower virulence
at predilection site but smaller, less moist nodules
(20-90% mortality)
Myxomatosis CS of Atypical/amyxomatous form
intensive farms
lower virulence strains
resp signs
very very few skin nodules
(83% mortality)
Myxomatosis diag
PCR
Myxomatosis vaccine
attenuated, before mosquito season (IM)
Fowlpox causative agent
Avian pox viruses
Fowlpox general description
lesions on skin & mucosa of domestic & wild birds
Fowlpox occurence
worldwide
Pheasant, turkey, pigeon & chicken
Fowlpox source of infection
wet rainy weather (pigeon & wild birds)
fall, winter time (chicken & turkey)
Fowlpox pathogenesis
Homologous strains:
* 1. per os, inhalation, skin lesion
* 2. primary asymptomatic replication (at the site of entry)
* 3. viraemia
* 4. organs, mucosa, skin (second replication site)
In case of survival:
* 5. secondary viraemia
* 6. replication in the skin (flourishing) Heterologous strains:
* Only primary replication
Fowlpox how many types
4
Cutaneous form local
diphteric (wet) malignant
mixed form
acute haemorrhagic form
Fowlpox, cutaneous local form
featherless areas
local lesions
animal usually recovers
Fowlpox diphteric malignant form
anorexia, coryza, conjunctivitis
Rep tract
membrane: nodule, converge and covered with fibrin-> anorexia wasting
death or recovery
Fowlpox mixed form CS
Pocks on the skin & mucosa
death or recovery
Fowlpox Acute haemorrhagic form CS
rapid death with no clinical signs
Fowlpox chicken CS
mainly diphteric
(imunized birds: resp signs without nodules)
Fowlpox turkey CS
diphteroid form, infertile eggs
Fowlpox Pheasant CS
resp signs
Fowlpox pigeon CS
diphteroid form
Fowlpox parrot CS
rare
conjunctivitis, ulcers around eye, necrotic ulcers in nasal cavity
Fowlpox vaccination
attenuated fowl/pigeonpox virus
Wing Web vaccination
