Upload
hassanqadeer
View
105
Download
0
Embed Size (px)
Citation preview
OUTBREAK INVESTIGATION IN CHUKAR PARTRIDGE
(Alectoris chukar)
Chukar:
Complaint:
• The farmer complained about the disease and death of birds
• Birds first show signs of disease by not eating ,huddling ,rattling sounds of trachea etc.
• For few days they remain sick then die.• Young birds are dying more than adult birds.• Disease erupted after introduction of some new
birds at the farm.
• Team of veterinarians visited the farm.• Farm is located in a remote area at Kathwai
District, Khushab where no other poultry farms are located nearby.
• Farm premises were clean but basic requirments of biosecurity were violated.
Signs of disease as observed by veterinarian:
• Tracheal rales• Nasal discharge• Coughing• Respiratory distress• sinusitis• Wt. loss• Reduced feed consumption• Male birds usually have more pronounced
signs.
Facts and figures:
• Total no of birds = 350• Affected birds =250• Morbidity rate=(250/350 )100=71 %• No of dead birds =86• Mortality=(86/350)100=24.5 %• Case fatality rate=(86/250)100=34.4 %
Tentative diagnosis:
• Chronic respiratory disease was suspected by looking at the signs and symptoms ,mortality pattern as well as age of birds.
• To confirm the disease postmortem was conducted and samples were collected for lab diagnosis.
Postmortem lesions:
• Air sacculitis• Pericarditis and perihepatitis• Catarrhal exudates in nasal passages ,
trachea ,bronchi etc.• Conjunctivitis
Sampling:• Bacterial Culture: Ocular and nasal swabs were • examined for the suspected bacterial
isolates .Samples were cultured on the nutrient broth, Mycoplasma broth base, broth and selenite broth.
• Later the cultures were transferred to nutrient agar, blood agar and MacConky’s agar plates for the isolation and purification of bacterial cultures.
• Bacterial cultures obtained from the pus were coccoid in shape.
• Fried egg colony.
Other tests:
• HI test• Tube agglutination test• Dx:• CRD caused by Mycoplasma gallisepticum was
confirmed by lab findings.
Discussion
Chronic respiratory disease is a disease of chicken, turkeys and other birds characterized by rales ,coughing ,nasal discharge(sinusitis) caused by Mycoplasma .
Mycoplasmas are prokarotes devoid of cell wall.M.gallisepticum is stained well with Giemsa and
is weakly gram –ve,coccoid in shape• Viability of MG:In chicken feces for 1-3 days at 20 C.On muslin cloth for 3 days at 20C or 1 day at 37C.In egg yolk for 18 weeks at 37C or 6weeks at 20C.
Susceptibility to chemical agents
• Most of the commonly used disinfectants effective against MG.
• Inactivated by phenol,formalin,B-propiolactone
• Virulence:• b/c of damage to host immune and
inflammatory responses rather than direct toxic effect.
• Transmission of the disease can occcur through direct or indirect contact of susceptible birds with infected clinical or subclinical birds.
• Here in this outbreak introduction of new birds caused the outbreak.
• History clearly dictates that newly introduced birds were non vaccinated ,looking apparently healthy caarying the disease in incubation period.
Vaccination:
• Various inactivated vaccines are available• Intramuscular inoculation is not satisfactory.• Respiratory route gives protection against
subsequent challenge.• MG seldom survives more than few days
outside the host, so carrier birds are very imp. to the MG disease
Intervention strategies:
• Adequate biosecurity to prevent the introduction of the organism at farm.
• Depopulation • Thorough cleaning and disinfection• 2-4wks vacant period b/w two batches of birds• Purchase MG-free day old chicks• Repeated inj. Of tylosin in oil+chlortetracycline
in feed is successful for prevention.
Conti….
• Avoid introduction of new birds,quarantine• b/c of egg transmision, start with stocks free
of the organism.• Establish MG-clean status of breeder flock.• As it is almost impossible to maintain MG-free
status ,therefore, appropriate antimicrobial therapy may be used.
• Vaccination of the flock
• Burry deep or burn properly the dead birds to avoid spread of disease.
• Disinfect the pens by spraying Sanitizer• Disinfect the water from any pathogen by
adding potassium per magnate @ 10gm/200 lit water for three days.
• Serologic monitoring of breeder flocks at short intervals (turkeys every 3wks, chicken every 2wks) would help in early detection to prevent egg transmission.
THANS