Poor health as a risk factor for tail biting ln pigs.

Poor health as a risk factor for tail biting in pigs. Tail biting is detrimental to animal welfare and has a negative impact on producer economy. We know that tail biting is a multifactorial problem with nutrition, feeding routines, pen design, pig density and the availability of manipulable material all influencing the net risk of a tail biting outbreak. Poor health has also been considered an important risk factor, but with less supporting evidence. Newer research within the EU collaborative project FareWellDock supports earlier findings and anecdotal reports that health does indeed influence the behaviour of pigs, and provides new knowledge about possible mechanisms. Up to now, the evidence pointing towards sickness increasing the likelihood of tail biting outbreaks has come from expert opinion and experience, epidemiological studies, case control studies and clinical reports. Farms with health problems are considered to have a higher risk of a tail biting outbreak and the risk of tail biting damage on farms with rectal prolapse and respiratory disease has been found to be increased. Clinical reports have stated that deworming and vaccination against Lawsonia intracellularis reduced tail biting while both leg disorders and respiratory inflammation were highly correlated with tail damage. These reports clearly show that there is an association between sickness and tail biting, but because tail biting may also lead to inflammation due to bacteria entering the wound, it is difficult to know what came first: poor health or a damaged tail. The issue is also further complicated by the fact that some risk factors for tail biting may also influence health.