Tail necrosis is a common swine affliction that occurs unpredictably and jeopardises performance. Tail necrosis can happen in very young piglets during the first days of life up to finishing pigs, often leading to culling and condemnation of carcases at the abattoir. The primary damage may result from abrasion, fight wounds or tail docking.
Causes of tail necrosis can be attributed to many environmental, nutritional and infectious agents that often coincide. A number of environmental factors can lead to tail necrosis including air humidity, small injuries from slatted or abrasive flooring, or a failure to rinse off strong (alkaline) disinfectants after use.
Pen mates may step on or bite the tail – a behavior more commonly observed with a lack of foraging activity or manipulating materials. High stocking density and competition for space also plays a role, potentially in response to discomfort caused by ambient temperature (too hot/cold), a lack of draught free areas, or in an effort to secure feeding space.
Cross-fostering, tail clipping and other environmental stressors may incite frustration from which vices such as tail biting develop. In terms of nutrition, an imbalanced diet, certain deficiencies, for example biotin or tryptophan, or a craving for salt, protein or some specific amino acids can influence tail necrosis. Excess energy and intestinal discomfort may also be contributing factors.
In some cases, naturally occurring toxins may be the cause, including endotoxins, mycotoxins (aflatoxin, trichothecenes, ergot alkaloids) and biogenic amines. Bugs can also be the culprit. Skin parasites (mites), streptococcosis (beta-haemolytic), staphylococcosis or erysipelas can be at fault. Bacteria penetrate into the skin causing inflammation and then block the blood supply, leading to necrosis. Prevention can be carried out by thoroughly revising management and feeding practices in order to avoid the identified environmental, nutritional and disease factors, and by maintaining good hygiene when tail clipping.
The only treatments that are available involve isolating the affected pigs and then providing local disinfection and parenteral antibiotics.