Conclusions

Pasteurella multocida can cause serious losses in adult broiler parent chickens, even if lesions are mainly localized in synovial sheaths and in the sub-cutaneous tissue of the head and wattles. A presumptive diagnosis was made on the basis of lesions and this was easily confirmed by bacterial isolations made in pure culture from the affected tissues. The low level of water maintained in the drinkers may have exacerbated mortality in this case. A rapid response occurred to tetracycline medication (long-acting oxytetracycline injections in selected birds and chlortetracycline in feed). Cannibalism was a secondary problem in 2 of the three sheds and this seemed to respond to soluble aspirin medication. An adaptation programme for the addition of extra males involving vaccination and antibiotic medication prevented the disease in these birds.