Diseases of commercial waterfowl

Question 1

List 4 viral diseases of Ducks

Answer 1

Duck viral hepatitis
Duck viral enteritis
Newcastle disease virus
Avian influenza

Question 2

List some bacterial diseases of ducks

Answer 2

E.coli
Pasteurella multicidia
Erysipelas
Salmonella
Staphylococci
Chlamydia

Question 3

What type of virus is duck viral hepatitis?

Answer 3

Picornavirus

Question 4

Which ages of ducks are most affected by duck viral hepatitis?

Answer 4

• 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

Question 5

Describe the spread of Duck viral hepatitis

Answer 5

• Entry into birds by ingestion
• Contaminated people, vehicles, equipment and other farm materials could spread the virus
• NO vertical transmission
• High morbidity within susceptible birds

Question 6

What are the clinical signs of duck viral hepatitis?

Answer 6

• Picornavirus strain causes death within 1 hour
• Opisthotonus (dramatic abnormal posture)

Question 7

List three DDx for duck viral hepatitis

Answer 7

Bacterial septicaemia
Duck Viral enteritis
Mycotoxicosis

Question 8

Describe the pathological lesions caused by duck viral enteritis

Answer 8

• Hepatomegaly, petechial haemorrhages
• Fatty kidneys
• Septicaemic carcass

Question 9

How is duck viral enteritis controlled?

Answer 9

Breeders – live and inactivated vaccines
Ducklings – live vaccination
Biosecurity and Management measures

Question 10

Duck viral enteritis is what type of virus?

Answer 10

Herpes virus

Question 11

Name the two hosts of duck viral enteritis

Answer 11

Ducks
Geese

Question 12

Which birds are most susceptible to duck viral enteritis?

Answer 12

Breeding birds

Question 13

How is duck viral enteritis spread?

Answer 13

• Presence of water essential
• Oral and cloacal routes
• Wild waterfowls can spread to domestic ducks
• Latency has been reported, virus shed for many years

Question 14

What are the clinical signs of duck viral enteritis?

Answer 14

Ataxia
Eye discharge, pasty eyelids
Nasal discharge
Diarrhoea – water with blood, vent blood stained
Photophobia
Normally body condition good

Question 15

Describe the lesions caused by duck viral enteritis

Answer 15

• Multiple haemorrhage in tissues
• Free blood in body cavity – particularly abdomen
• Petechial haemorrhages on visceral organs
• Haemorrhage on oesophageal mucosa, other GIT
• Necrotic foci on liver and oesophagus

Question 16

How is duck viral enteritis diagnosed?

Answer 16

• History, clinical signs and lesions, eg. significant drop in egg production
• Virus isolation confirmatory
• PCR

Question 17

How is duck viral enteritis controlled?

Answer 17

• Biosecurity
• Avoid contact with wild birds
• Vaccination

Question 18

Describe the signs of avian influenza in waterfowl in the UK

Answer 18

• Small increase in mortality
• Drop in egg production, little slowly to 30%
• Decreased in feed and water consumption
• Little subdued

Question 19

Describe Newcastle disease in ducks

Answer 19

• Ducks are relatively resistant to NDV
• Common problem – major drop in egg production
• No clinical signs in younger birds
• Vaccination works well

Question 20

Describe E.coli infections in ducks

Answer 20

• Mostly from environment
• 1-8 weeks old young birds susceptible
• Egg peritonitis in laying birds

Question 21

How are E.coli infections in ducks diagnosed?

Answer 21

history, clinical signs, necropsy, laboratory support

Question 22

How are E.coli infections in ducks treated/prevented?

Answer 22

Treatment – antibiotics
Prevention
- Hygiene and sanitation
- Management
- Vaccinate breeders

Question 23

Riemerella anatipestifer causes what lesions in the body?

Answer 23

Polyserositis, exudates and fibrin covering visceral organs, cavity
Lymphoid necrosis of the white pulp of spleen

Question 24

What is polyserositis?

Answer 24

Inflammation and effusion of the pericardium, pleura or peritoneum

Question 25

Describe salmonella infections in ducks

Answer 25

Little clinical signs
Infrequent mortality 0-7 days-old
Vertical and horizontal transmission

Question 26

How are salmonella infections in ducks treated/prevented?

Answer 26

• Live and inactivated vaccines
• Antibiotics
• Competitive exclusion
• Hygiene and sanitation, biosecurity at breeding farm and hatchery important

Question 27

Describe Chlamydia infections in ducks, including clinical signs

Answer 27

All ages can be affected
C psittaci - zoonotic
Clinical signs – conjunctivitis, anorexia, ruffled feathers

Question 28

How are chlamydia infections in ducks treated/prevented?

Answer 28

No vaccine available
Antibiotics
Hygiene and sanitation, biosecurity at breeding farm and hatchery important

Question 29

What is the source of Aspergillosis fumigatus?

Answer 29

Contaminated environment – litter, feed

Question 30

What are the clinical signs of Aspergillosis fumigatus in ducks?

Answer 30

Gasping, weight loss, anorexia, death
Stress exacerbates susceptibility and disease

Question 31

How is Aspergillus fumigatus treated/prevented?

Answer 31

Use of fresh bedding materials
Anti-fungal, in-feed
Hygiene and sanitation, biosecurity at breeding farm and hatchery important