Cellulitis in broilers can lead to major losses due to down grading of the product in the processing plant.
The conditions is caused by bacterial contamination in and under the skin. These bacteria (mainly e-coli) are entering through small lesions that are caused by scratches and damage of feather follicles.This means that for possible causes and solutions one should look at the integrity of the skin, the non-specific immune system of especially the skin and the level of infection pressure.
In general all breeds seem to be affected more or less evenly, but lines selected for slower growth seem to have less issues with it, perhaps because of a more active non-specific immune system or because of differences in the skin structure. Feather coverage plays a role as well, as poor feather coverage will create more skin lesions. One would expect that some commercial dwarf lines will have less problems as well due to a difference in skin rigidity, but exact information is not to the author's knowledge.
Damages of the skin can occur mainly through scratching, as a result of over crowding at feeders or drinkers. Stocking density, feeding regimes but also too exttreme dark periods will leave the birds hungry and will induce crowding at the feeder lines. Also water restriction programs can have similar effects on the drinker lines. Too high light intensities and stirring up the birds during inspection and control can result in skin damage as well. Vaccinations should be done preferably in the hatchery.
The non-specific immunity in the skin can play a role. Reduced cellular innate immunity (reduced activity of phagocytes) can be a factor. Reserarchers in Canada have found that cellulitis is related with a poor structural quality of the skin, which can be caused ty a poor protein metabolism. Poor bone development and bone degeneration can be an indicator for this, probably due to a poor protein metabolism.
The level of infectious pressure will play a role, which means that litter quality is an issue. Ventilation, feed quality and gut health need to be taken into account..