Disease Fact sheets 1

Question 1

Ascites species, importance, etiology

Answer 1

• Metabolic disease of fast growing broiler chickens. Occasionally seen in commercial turkeys.
• One of the most common and economically important diseases of commercial broiler chickens. It causes significant losses both in the growing period and via condemnations at processing.
• Ascites is a disease of complex etiology associated with rapid growth and insufficient oxygen reaching the tissues.

Question 2

ascites pethogenesis

Answer 2

• broiler rapid growth > limited lung capacity cannot supply oxygen for metabolic needs > increase red cells > viscous blood, cant pass through lung capillaries > high pressure, pulmonary hypertension > right sided heart dilation, impaired function > blood pressure backs up to liver > hepatic congestion > ascites

Question 3

how does ascites get worse?

Answer 3

• anything that increases metabolic demand for oxygen
  > high altitude, cold climates

Question 4

ascites lesions

Answer 4

heart right ventricular thickenning, and then dilation, incompetent AV valve > right sided HF

Question 5

ascites treatment

Answer 5

• cull, as they will grow slow and be condemned

Question 6

ascites prevention

Answer 6

• Slow the growth rates. Decreasing feed density during the first portion of the growth phase.
• ensure good ventilation and temperatures
• proper lighting program > slower initial growth reduces late cycle metabolic issues (restricted feeding in dark period)

Question 7

aspergillosis disease, dx, transmission, treatment

Answer 7

• acute or chronic
• associated with stress and immunosuppression or massive exposure
• localize in the respiratory tract
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  Most commonly, Aspergillosis is a chronic disease with wasting, innapetance and respiratory signs
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  visualization of typical hyphae using techniques like endoscopy, biopsy, sinus, tracheal or air sac lavage and radiology.
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  can be caused by incubator or hatcher contamination. Baby birds infected in this way are referred to or having “brooder pneumonia” in the turkey industry
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  Systemic antifungal agents like Itraconazole, fluconazole or flucytosine or I.V. amphotericin B. Amphotericin B has also been used via nebulization.
  ∗ supportive care is always necessary.
• prevention: Good husbandry.

Question 8

avian influenza
- who is affected? do all show signs?
- importance?

Answer 8

• Chickens, turkey clinically affected.
• Ducks and many other species rarely show clinical disease, but may carry the virus.
• There are reports of AI in psittacine species with dyspnea and depression being the clinical signs
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  Only the highly pathogenic strains are federally reportable, but all strains may cause economic loss due to reduced international trade.

Question 9

AI etiology, clinical signs?

Answer 9

• Orthomyxovirus
• high mortality
• clinical signs ranging from severe depression to severe respiratory signs and discoloration and swelling of combs wattles and legs.
• Lesions at necropsy may be found in many organs and can resemble those of Newcastle disease.

Question 10

AI treatment

Answer 10

• no treatment
• prevention is through strict biosecurity
  > There are no vaccines commercially available in Canada.

Question 11

E. coli in poultry - who is most affected? significance?

Answer 11

• particularly important in commercial broiler chickens and turkeys.
• Colibacillosis and respiratory infection are perhaps the most economically important disease in commercial poultry
• E.coli is also a common pathogen causing septicemia and localized infections in pet birds.

Question 12

E. coli etiology, disease, transmission

Answer 12

• there are many serotypes: 1, 2, 78 are the most common pathogenic types in poultry
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• Colibacillosis - Acute septicemic E. coli infection of young growing broiler chickens or turkey poults.
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• Young birds may be infected in the hatchery and these birds develop naval infections and omphalitis.
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• Pathogenic E. coli may survive in barns between crops or it may be tracked into the barn through breaches in biosecurity.
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• cellulitis

Question 13

cellulitis cause, significance
- risk factors

Answer 13

• inoculation of E. coli through scratches on the backs of the birds as they crowd around feeders and water drinkers.
• top cause of condemnations in broilers
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• overcrowding, inadequate feeder or drinker space per bird and the selection for fast body growth and slow feathering.

Question 14

E. coli treatment, prevention

Answer 14

treatment
- Antibiotics as per sensitivity testing.
- Good husbandry and a high level of barn sanitation.
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prevention
- Biosecurity, good barn management (ventilation and litter quality).
- for cellulitis, risk factors include overcrowding, inadequate feeder or drinker space per bird and the selection for fast body growth and slow feathering.

Question 15

Exotic Newcastle Disease importance, etiology

Answer 15

• Reportable Disease in most countries of the world
• Paramyxovirus (PMV1)
• Most countries will only import poultry from other countries proving to be Newcastle Disease free

Question 16

reportable diseases in Canada

Answer 16

• Newcastle disease (exotic Newcastle, Velogenic Newcastle)
• Avian Influenza (high pathogenicity)
• Salmonella pullorum
• Salmonella gallinarum
• Salmonella typhimurium DT104 (if human involvement)
• Salmonella enteriditis

Question 17

newcastle disease signs

Answer 17

• neurologic signs
• high mortality and morbidity
• GIT lesions often associated with gut associated lymphoid tissue
• Central nervous system lesions, non- suppurative encephalitis
• Embryo mortality

Question 18

newcastle disease strains

Answer 18

• velogenic (reportable)
• mesogenic
• lentogenic (many vaccine strains)

Question 19

control of newcastle disease: federal compensation

Answer 19

Federal control: eradication and compensation for birds and contact materials such as left over feed, crates etc.
Compensation amounts are based on a preset fee schedule but exotic or pet birds result in a price negotiation.

Question 20

newcastle control

Answer 20

• Virtually every broiler breeder flock, layer flock and turkey flock are vaccinated against Newcastle Disease
• Broilers are done less consistently due to their short grow out period
• Multiple vaccines: usually live lentogenic strains of virus early (2-3 boosters) followed by killed, oil immulsion vaccine prior to entering breeding cycle.

Question 21

HPAI etiology and vaccination? control strategy?

Answer 21

• Orthomyxovirus
• High ability of mutate and alter itself making vaccination almost impossible except in local regions
• The ability to mutate causes great grief as only the high pathogenicity strains are federally reportable, yet the industry clearly needs some policy to deal with the other strains that don’t qualify as high path strains

Question 22

AI signs

Answer 22

• AI may present with respiratory or nervous signs
• In layers there is a marked drop in egg production
• High morbidity and high mortality in the high path strains

Question 23

AI control and prevention

Answer 23

Control is through tight Biosecurity
* There is no vaccine
* Vector control critical
* Wild birds may be a source and waterfowl are common asymtomatic carriers of AI virus (although rarely with pathogenic serogroups)

Question 24

AI transmission

Answer 24

Birds become infected with AI when they have direct contact with diseased or carrier birds.
Infected birds may shed the virus in their feces, contaminating the environment. The virus can survive for days in litter, feed, water, soil, dead birds, eggs and feathers.
The disease spreads rapidly among birds in close confinement. AI can be brought into a poultry barn by breaches in biosecurity and is most often transmitted from one infected flock to another by movement of infected birds or contaminated equipment or people.

Question 25

Clinical signs of infected birds with AI may include:

Answer 25

• decrease in feed and water consumption
• extreme depression
• drop in egg production (many of which are soft-shelled or shell-less)
• high and sudden morbidity and mortality rate
• signs of septicemia:
  o hemorrhages on the hocks
  o severe edema of eyelids, wattle and combs
  o hemorrhagic enteritis

Question 26

Key steps to reduce the risk of infection with AI in your flock include:

Answer 26

• Ensure adequate training of farm and company personnel in biosecurity and disease
  prevention.
• Require all people entering poultry barns, including farmers, employees and service
  providers to put on clean footwear and protective clothing and to follow all biosecurity
  protocols each time a barn is entered.
• Minimize visits to other poultry production sites and avoid any commingling of
  birds or contact with outside/wild birds.
• Avoid exchanging and sharing equipment with other poultry production sites or farms.
• Ensure all vehicles and farm equipment that access the barn vicinity are properly
  washed, disinfected and thoroughly dried before use.
• Ensure that laneways are restricted and secured.
• Prevent wild bird and rodent entry to poultry barns and related facilities.
• Ensure that bedding is free of contaminants (such as feces from wild animals)
• If possible, “heat treat” the barn/litter ahead of chick or poult placement (to 38°C for
  at least 4 days).
• Keep all domestic poultry in doors during the high-risk period of fall migration”
• Do not attend events where birds from different locations are brought together
  including shows, fairs, swaps, sales and events such as pigeon racing. Commingling
  birds from various locations increases the risk of disease spread, including diseases
  such as avian influenza.