Growing Period
RESPIRATORY

CASE HISTORY, FLOCK #2

      Twenty-six week old caged layers had a sudden onset of severe respiratory disease.  Only one house is involved on this multiple age, multiple house complex.  Mortality was normal until today; this morning 250 birds were found dead.  Morbidity is 10%.  All affected birds are in the middle of the house; the clinical signs are slowly spreading from this focus.  Clinical signs included expectoration of blood stained mucus, gasping for air and violent head shaking.

      This flock was vaccinated with a combination NDV-IBV vaccine at 2, 4, and 12 weeks.  Beaks were trimmed at 8 weeks at which time they were also vaccinated for laryngotracheitis (LT), pox and avian encephalomyelitis (AE). LT was given again at
15 weeks of age.

 

CLINICAL SIGNS, FLOCK #2

      Twelve (12) birds were presented for diagnosis.  All were gasping for air.

Important Information:

 

DIFFERENTIAL
DIAGNOSES (DD)

EXPECTED POST MORTEM
FEATURES FOR EACH 
BEST CONFIRMED BY
WHAT FURTHER WORK-UP

 

POSTMORTEM EXAM, FLOCK #2

Tracheal lesions were evident in all birds.

12/12      Bloody pseudo-membranes in trachea and/or larynx
6/12     Mucocaseous tracheal core
2/12     Sinusitis, nasal discharge and infraorbital swelling
8/12      Conjunctivitis

 

Updated differential diagnosis (based on clinical history and postmortem findings) list the most likely first.

 

What further laboratory tests would you run to confirm your diagnosis?

 

Treatment (for each differential listed)

 

 Prevention (for each differential listed)