An outbreak of acute localized Pasteurellosis in broiler parent chickens (20-26 weeks of age).

Paul Mc Mullin MVB DPMP MRCVS
Poultry Health Services (formerly Hillsdown Veterinary Services)
Marsh Lane, Hemingford Grey,
Huntingdon, Cambs PE18 9EN
SUMMARY

An ongoing problem of mortality in 25 week old broiler parent chickens was confirmed to be due to acute localized Pasteurella multocida infection in the sub-cutaneous tissue of the head and wattles and in joints and tendon sheaths. This case report describes in detail the clinical signs and lesions encountered, and the results of bacteriological and serological examinations. Previous antibacterial treatments only partially controlled the problem. An action plan was formulated to include:
In-feed and individual antibiotic medication, short term and as an ongoing programme.
Review of the environment to maximize bird comfort (drinkers, bedding, lighting).
Preparation of supplementary males in such a manner as to maximize their chances of being a useful addition to this flock (to include vaccination, antibiotic cover, and timing).
This programme resulted in a rapid reduction in the mortality of males and an improvement in appearance of the birds. Cannibalism-related mortality continued in 2 houses. A short course of soluble aspirin in these two houses seemed to improve bird comfort and was associated with a reduction in mortality.

The Complaint
The History
Mortality Patterns
The Investigation
Differential Diagnosis and Diagnosis
Treatment and Advice
Follow-up Information
Literature Review and Discussion
Conclusions
References

Acknowledgements
Thanks are due:
To poultry company management and farm staff for their enthusiastic help in collecting much of the information presented here.
To S. Smith of Hoechst Animal Health for arranging the sero-typing performed by Mr P.D. Foster of VPLS, Spratton
To C. Randall for histological examination