Download Fowl Cholera

Fowl Cholera
(Pasteurellosis, avian hemorrhagic septicemia)
Fowl Cholera is a serious, highly contagious disease.
 All species of fowl affected
 Both acute (primarily in turkeys) and chronic (primarily in chickens) infections
occur..
 Young adults and mature birds usually affected.
Etiology:
 Pasteurella multocida
 Gram-negative bacteria, non motile, non-spore forming rod
 The most important bacterial infection in turkeys. Will survive 3 months in
carcass.
Species affected:
 Domestic fowl of all species (primarily turkeys and chickens)
 Game birds (especially pheasants and ducks).
 Cage birds, wild birds.
Other Avian Pasteurellas
 Pasteurella anatipestifer (ducks)
 P. haemolytica (colonies have B-hemolysis)
 P. gallinarum (in mixed chronic respiratory infections) are also pathogens and
may cause disease in poultry and waterfowl.
Epidemiology:
 The incubation period is usually 5-8 days.
 Usually strikes birds older than 6 weeks of age.
 Morbidity and mortality may be up to 100%.
 The bacterium is easily destroyed by environmental factors and disinfectants,
but may persist for prolonged periods in soil (2 to 3 months) and at least 1
month in droppings.
 Reservoirs of infection may be in other species such as rodents and cats.
 Predisposing factors include high density and concurrent infections such as
respiratory viruses.
Transmission:
 The route of infection is oral or nasal with transmission via nasal exudate,
feces, contaminated soil, equipment, and people.
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 Free-flying birds, rodents (rats and mice).
 No transmitted through the egg.
Clinical signs:
- In acute form (acute septicemia):
 Sudden death may be the first sign.
 Dejection and ruffled feathers.
 Loss of appetite, fever.
 Mucoid discharge from the mouth.
 Diarrhea.
 Coughing and labored breathing.
 Nasal and ocular discharge.
 Swollen and cyanotic wattles and face.
 Lameness.
 Birds lose weight.
- Chronic form (localized pasteurellosis): not cause high mortality,
 Swollen abscessed wattles.
 Swollen sinuses.
 Swollen joints and foot pads.
 Tracheal rales and dyspnea
 Torticollis resulting from meningeal infection (especially in turkey).
Post-mortem lesions:
 General hyperemia (in veins of the abdominal viscera, in small vessels of the
duodenal mucosa).
 Petechial and ecchymotic hemorrhages (sub-serosal hemorrhages in the lung,
abdominal fat and intestinal mucosa.
 Enteritis.
 Enlarged liver with foci of necrosis.
 Purulent pneumonia (especially turkeys).
 Cellulitis of face and wattles.
 Caseous exudate in the sinuses around the eyes.
 Purulent arthritis.
 Yolk peritonitis.
 Lungs with a consolidated pink 'cooked' appearance in turkeys.
- In chronic fowl cholera:
 Cheesy exudates can be found between the intestines, and on liver and heart.
 Yellowish caseous exudate in air spaces of the calvarial bones.
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Diagnosis:
 Signs and lesions
 Isolation (aerobic culture on trypticase soy or blood agar yields colonies in 24
hours - no growth on McConkey), confirmed with biochemical tests.
 Serologic method:
- Rapid whole-blood agglutination.
- Serum plate agglutination.
- Agar diffusion tests.
- ELISA has limited value in chronic cholera and no value with the acute form
of the disease.
Differential diagnosis:
 Erysipelas
 Septicemic viral and other bacterial diseases.
Treatment:
 Treat in water if possible.
 Drug of choice – Sulfadimethoxine (Albon) use as directed by drug company.
Preslaughter withdrawal 5 days.
 Sulfaquinoxaline is effective but toxic – withdrawal 10 days.
 INJECTIONS:
 Penicillin – Streptomycin combination 25 mg Dihydrostreptomycin and
500 units Procaine Penicillin G for each pound of body weight.
Prevention
 If the turkeys are 12 weeks of age or less, vaccinate with live vaccine and treat
in 4 or 5 days.
 Birds should not be treated 72 hours previous to vaccination or for 4 days post
vaccination.
 Live field attenuated strain – CU strain good results in turkeys and chickens.
 Vaccinate turkeys in drinking water at 6-7 weeks Then every 3-5 weeks (once
a month). Make sure watering systems are free from chlorine which will
inactivate the vaccine.
 M-9 – attenuated CU – used in turkeys and chickens. So mild it is not
recommended. Less immunity than CU but also less side effects.
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 All live vaccines must be injected in chickens (wing web route). Oral
vaccines given in the water are used in turkeys.
 Killed vaccine – limited success in turkeys. Inoculated I/M or S/Q at 10 weeks
or older and boost from 3 to 10 weeks later.
 Both aqueous and oil emulsion products available. Usually used in layer or
breeder chickens.
 Live vaccines give a broader spectrum of protection. Vaccinate hens with live
vaccine by the wing web “stick” method. Use PM-1 or CU strain vaccine and
pox inoculation needle.
*Do not vaccinate for fowl cholera unless you have a problem on the farm.
Dr. firas Hussien dept. of pathology.
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