9. Derzsy’s disease of geese, parvoviral disease of ducks Flashcards
Derzsy’s disease info?
_*NOTIFIABLE*_
• Goose influenza, goose hepatitis, goose parvovirus enteritis
Etiology
- Goose and muscovy duck
- Severe in young (acute, high mortality), depends on yolk immunity
- Negligible losses over 5 weeks
Epizootiology
- Known since the end of the 19th century
- Etiology: virus classified by Derzsy (1970)
- Became endemic on large farms
- Present everywhere, frequent disease
- Recently a parvovirus enteritis of growing geese
Goose parvovirus morphology?
Goose parvovirus
- Parvoviridae, Parvovirinae, Dependoparvovirus, Goose parvovirus GPV
- Uniform structure of antigen
- Embryonated eggs, primer tissue cultures CPE
- VP1-VP3 identical
- Dependoparvovirus BUT! Does not need helper virus
Goose Parvovirus Pathogenesis?
Pathogenesis
- Viral intake: per os
- Viral replication: small intestinal epithelia
- Viraemia (sort)
- Parenchymal organs: liver, heart muscle
- Shedding of the virus with faeces from days 3-4 (7-10 days)
- Horizontal
‣ Faeces, recovered but long-term shedding geese
‣ Directly or not
- Vertical
‣ Subclinical infection of the parents
‣ Infected old geese
‣ Clinical signs below 5 weeks of age: later can also be infected but without signs
๏ Embryo dies
๏ Hatches infected
Goose parvovirus Clinical signs?
Clinical signs
- Susceptible goslings: infection at hatching at day 1 of age
‣ 1 week incubation
‣ Death within 1-2 days
‣ Peak mortality at the end of week 2 (50-60%)
‣ Anorexia, lethargy, feather growing problems
‣ High water consumption
‣ Cold like symptoms, swollen eyelids, nasal discharge
‣ Diarrhoea, profuse, whitish pseudomembranes on tongue
‣ Convulsions (liver damage)
‣ Ascites
‣ Occasionally dominated by diarrhoea and exsiccosis
- Partially protected goslings: signs appear at the end of week 2, peak at end of week 3
‣ Development and growth stops
‣ Feather growing problems on back, receding hair, redness of skin
‣ Ascites
- Day 13-15
‣ Diarrhoea
‣ Exsiccosis (intact liver and heart)
- Survival at 5-6 weeks
‣ Development and growth stops
‣ Feather growing problems
Goose Parvovirus Pathology?
Pathology
- Ascites (rich in fibrin)
- Swollen liver, spleen and pancreas
- Ball shaped heart, tiger stripes
- Haemorrhages on membranes
- Hepatitis, Pericarditis and perihepatitis, Enteritis
Diagnosis of Goose parvovirus?
Diagnosis
o Clinical condition, post mortem examination
o Virus detection: IF, IP, PCR, isolation
Ab detection: iIF, ELISA, VN (up to 1:1600 is from vaccination)
Differential diagnosis and prevention of Goose parvovirus?
Differential diagnosis:
- Riemerellosis
- Haemorrhagic nephritis enteritis of geese
Prevention:
- Epidemiology
- No treatment, antibiotics against the secondary infections
- Vaccines: obligatory to vaccinate breeder geese in most countries
- Attenuated, inactivated or subunit
- Recombinant: barbari duck parvovirus antigens, 1 month before laying season 1x
- Re-vaccinate layers, especially before the end of the laying season (Protection up to 4 weeks old)
- Passive protection (hyperimmune serum) for day old goslings
Duck parvoviruses?
Duck parvoviruses
- Parvoviridae, Parvovirinae, Dependoparvovirus, Duck parvovirus DPV
- Similar to Derzsy disease
- Barbari duck, mucovsky duck can be infected, BUT geese are not
- Genetically and structure of the antigen is relative to GPV
- Pathomechanism, diagnosis, prevention like Derzsy disease
Clinical signs of Duck parvoviruses?
Clinical signs
- One week-old
- Lethargy, bedraggled feather
- Diarrhoea, weakness in the legs (laying down), Nervous system
- 30-60% mortality, death at 2-5 weeks
- Chronic cases: development and growth stops, feather growing problems
Pathology of Duck parvoviruses?
Pathology
- Acute: enlarged liver
- Chronic: enlarged liver and kidney
- Muscles look like cooked meat
- Ball shaped heart
- Ascites
- In the liver, heart, muscles, brain, n. ischiadicus: inflammation with histio-lymphocytes
- Short beak & dwarfism syndrome (SBDS)
- Duck parvovirus, Mucovsky duck, From 1970
