Factors associated with footpad dermatitis in German laying hens: A retrospective study

Footpad dermatitis (FPD) is characterized by lesions on the plantar region of the footpad. It is one of the most common foot health problems and welfare issues mainly described for broilers and turkeys. This retrospective study aimed to evaluate the presence of this footpad disorder in laying hens as well as to identify typical risk factors for FPD during the laying period. Data were collected from 39 German laying hen flocks visited up to 16 times during production, where the housing system, flock size, age of flock, season, litter type and quality as well as hens' foot health were recorded in 30–200 randomly selected animals/visit using a four-point scoring system (FPD-Score 0–3). In total, 15,448 randomly selected laying hens were scored and classified, recording the highest degree of FPD per animal as well as whether FPD was detected in one or both of its feet. Of the hens examined, 78.9% showed no alterations, 18.6% showed slight ones, 2.2% moderate alterations, and 0.3% showed severe FPD. In the animals related to FPD (n = 3253), 48.0% of the hens showed an alteration in one foot and 52.0% in both feet. While few animals showed FPD at the first two visits (AF0, AF1), the percentage of animals related to FPD increased at the laying peak (~28th week of life). At the end of the laying period, 34.4% of the hens showed at least slight alterations (n = 955/2776). The results of the statistical analysis showed that the FPD-Score was statistically affected by the type of litter, the season, and the age of flock (all P < .0001), while the quality of litter at the time of visit (P = .0940), the housing system (P = .2696), and flock size (P = .8776) were not related to FPD. In summary, this study detected that more than a third of the animals examined showed alterations in their footpads at the end of the laying period. Such changes in foot health occurred from the laying peak and increased to the end of the laying period. In addition to the age of the hens, the type of litter and the season were determined as potential risk factors. Moreover, this study shows how common this foot health problem is, not only in turkeys and broilers but also for laying hens.