Dx of commercial waterfowl

What is the process of duck production?

What are the viruses that can affect ducks?

• Duck viral hepatitis(DVH)

• Duck viral enteritis (DVE)

• Newcastle disease

• Avian Influenza

What are the bacterial agents that can affect ducks?

• E. coli

• Riemerella anatipestifer

• Pasteurella multocida

• Erysipelas

• Salmonella spp

• Streptococcus spp

• Chlamydia

What is the main fungal agent that can affect ducks?

Aspergillosis

What is the biggest non infectious issue in duck production?

Lameness

What virus causes duck virus hepatitis (DVH)?

Picornavirus

What age ducks does DVH tend to affect?

• Highly infectious in ducklings, acute onset

• Most affecting ages of 2 days to 3 weeks old

• Adults birds are immune to infection, 7+ weeks completely immune

What are the three different types of DVH?

• Type 1 - picornavirus (classical disease), widespread and virulent

• Type 2- astrovirus

• Type 3- picornavirus- no cross protection with 1

Type 1 & 3 most important (resistant & viable for weeks to months in environ)

How is DVH spread?

• By ingestion, contaminated people, vehicles, equip & other farm materials

• No vertical transmission

• High morbidity within suscep birds

What are the clinical signs of DVH?

• Type 1 peracute death within 1 hour

• Dead birds in good condition

• Opisthotonus

• Mortality >90% (5-10% in endemic areas because of slow exposure and partial immunity)

• Type 3 similar signs but <30% mortality

What are the Ddxs of DVH?

• DVE

• Bacterial septicaemia

• Mycotoxicosis

What are the PM lesions associated with DVH?

• Liver enlarge, petecchial/ecchymotic haemorrhages

• Fatty kidneys

• Septicaemic carcasses

How is DVH diagnosed?

• Blood/organ for virus isolation in eggs

  • (No PCR, No commercial serology)

How is DVH controlled?

• Breeders – live and inactivated vaccines

• Ducklings – live vaccination

• Biosecurity

• Management measures

What type of virus is duck virus enteritis?

Herpesvirus

What are the hosts of DVE?

Ducks, geese

• Breeding birds more susceptible

How is DVE spread?

• Presence of water essential

• Oral and cloacal routes

• Wild waterfowls can spread to domestic ducks

• Latency has been reported, virus shed for many years

What are the clinical signs of DVE?

• Ataxia

• Eye discharge, pasty eyelids

• Nasal discharge

• Diarrhoea – water with blood, vent blood stained

• Photophobia

• Normally body condition good

What are the PM lesions associated with DVE?

• Multiple haemorrage in tissues

• Free blood in body cavity

• Petechial haemorrhages on visceral organs

• Haemorrhage on oesophageal mucosa, other GIT

• Necrotic foci on liver and oesophagus

How is DVE diagnosed?

• History, clinical signs and lesions, eg. significant drop in egg production.

• Virus isolation confirmatory

• PCR

• (No routine serology)

How is DVE controllled?

• Biosecurity

• Avoid contact with wild birds

• Live vaccine (risk of reversion to latency possible)

• Inactivated vaccine

What are the subdivisions of avian influenza?

(divided by pathogenicity):

• LPAI

• HPAI (notifiable)

What are the clinical signs of HPAI in ducks?

Ducks naturally more resistant to HPAI

• Small increase in mortality

• Drop in egg production, slowly to 30%

• Decreased in feed and water consumption

• Subdued

What are the necropsy findings of avian influenza?

Aspergillosis, airsaculitis, salpingitis, egg peritonitis

How does newcastle dx affect ducks?

• Relatively resistent

• Major drop in egg production is main sign

• No clinical signs in younger birds

How is newcastle disease controlled in ducks?

Live and inactivated vaccines (works well)

In what age birds does E. coli affect?

What does it cause?

• Any age but mostly 1-8 week old young birds suscep

• Causes egg peritonitis in laying birds

How is E. coli diagnosed?

• History

• Clinical signs (dull, ruffled feathers, diarrhoea)

• Necropsy

• Lab support

How is E. coli treated?

ABs

How is E. coli prevented?

• Hygiene & sanitation

• Management

• Vaccinate breeders (autogenous)

What age birds does streptococcus gallolyticus affect? ***

10-21 days old young birds susceptible

What signs does streptococcus gallolyticus show? ***

• Acute deaths- body condition good

• Causes bacteraemia in intensively reared ducklings

How does streptococcus gallolyticus present on PM? ***

• Viscere congested

• Cyanosis

• Oedematous lungs

• Hepatomegaly

• Mottled splenomegaly

How is streptococcus gallolyticus treated and prevented? ***

Tx- antibiotics: amoxicillin

Prevention: hygiene, sanitation, management

What PM lesions does Riemerella anatipestifer cause?

• Polyserositis, exudates & fibrin covering visceral organs, cavity

• Lympoid necrosis of the white pulp of spleen

How is Riemerella anatipestifer diagnosed?

Bacteriology, by culture, isolation and identification

How is Riemerella anatipestifer treated?

• Good response to ABs

• Autogenous vaccine

What are the two species of Salmonella that affects waterfowl?

S. indiana, S. kedougou

What are the signs of Salmonella infection? How is it transmitted?

• Little clinical signs

• Infrequent mortality 0-7 days-old

• Vertical & horizontal transmission

How is salmonella diagnosed?

c/signs, lesions, bacteriology

How is salmonella treated and prevented?

• Live & inactivated vaccines

• ABs

• Competitive excluson

• Hygiene & sanitation, biosecurity at breeding farm and hatchery important

What species of chlamydia causes infection? What ages can be affected?

• C. psittaci (zoonotic)

• All ages

What are the clinical signs of chlamydia infections?

• Conjunctivitis

• Anorexia

• Ruffled feathers

How is chlmaydia infection diagnosed?

• c/signs

• lesions

• bacteriology

• serology

How is chlamydia treated and prevented?

• No vaccine available

• ABs

• Hygiene & sanitation, biosecurity at breeding farm & hatchery important

How is aspergillus fumigatus transmitted?

Contaminated environment – litter, feed

What age birds does aspergillosis affect?

7 days to adult

What are the clinical signs of aspergillosis?

• Gasping, weight loss, anorexia, death

• Stress exacerbates susceptibility & disease

How is aspergillosis trasnmitted?

Vertical & horizontal transmission

How is aspergillosis diagnosed?

• C/ signs

• Lesions

• Mycology

• PCR

How is aspergillosis treated and prevented?

• Use of fresh bedding materials

• Anti-fungal, in-feed

• Hygiene & sanitation, biosecurity at breeding farm and hatchery important

List some common problems causing lameness

• Soft tissue injury

• Foreign body

• Join infection

• Osteoarthritis

• Fractures

• Mycoplasma tenosynovitis

• Renal/gonadal neoplasia

• Renal coccidiosis

• Heavy metal toxicity

• Bumble foot

• Avian TB