Tail Necrosis in Pigs
Signs, causes, prevention and treatment
Pig tail necrosis is a common and unfortunate problem that occurs unpredictably and can compromise the performance of both young piglets and finishing animals. Depending on the severity, it may lead to higher carcass condemnation rates and negatively affect profitability.
Signs
The tail of a piglet varies greatly in length, between 5 and 13 cm and averaging 9 cm. In young piglets, tail necrosis begins as a constricting ring of dead tissue that then restricts the blood supply from this point onward to the extremity. The tail has a brown, rigid, retracted, and brittle wound that breaks easily. Another early presentation of this necrotic tissue may occur at the tip of the tail, whether cut as a management practice or not, and gradually moving toward its insertion.
Bacterial causes
In many cases, the occurrence of tail necrosis is associated with bacterial dermatitis such as those caused by Staphylococcus hyicus, Streptococcus β hemolytic and Erysipela sp. One of these agents penetrates the skin, generates inflammation that can block blood circulation to the extremities and, consequently, tissue death.
Associated with secondary bacterial contamination is a primary lesion that may originate from:
- Floor abrasiveness when looking for the nipple during lactation
- Fights and injuries from piglets' sharp that can inoculate bacteria from the oral cavity as well as from the body surface
- Tail cutting by contaminated equipment
- Poor cauterization of remaining stump allowing for a continuity solution
Lesions
In larger swine, extremity necrosis is a common sequela of systemic infections due to arterial damage that decreases blood supply or may occur as a type III hypersensitivity reaction, with accumulation of antigen/antibody complexes that occlude the capillaries. Such lesions usually occur after an outbreak of the disease and can be seen in convalescence.
These types of lesions are observed in association with Erisipela sp., Haemophilus parasuis, and systemic Salmonella sp. Infections, but may also occur as part of porcine circovirus type 2 dermatitis and swine nephropathy syndrome.
Environment
Environmental factors may also explain the occurrence of ear necrosis. Relative humidity, minor injuries from slatted floors, residual alkaline disinfectants on site are some examples.
Management
Regarding management, pigs may tread or bite their tail due to lack of interaction with fibrous materials or environmental enrichment. High density, competition for space also play a role, potentially in response to discomfort caused by too low or too high ambient temperature, presence of drafts or contention for access to the feeder. Animal transfer and other environmental stressors can lead to frustration and, consequently, tail biting. [Read how to Successfully Eliminate Tail Biting in Pigs to Improve Herd Performance].
High density reduces antibody levels in pigs, affecting colostrum and sow milk production, and may further increase the problem. Piglets also ingest endotoxins from their mother's milk and this was also found by the researchers to be responsible for inflammation and necrosis in the ears and tails of the piglets.
Endotoxins
The prevalence of endotoxins also tends to depress liver and kidney functions. One effect of this is that the efficiency of blood clotting is reduced, which in turn further aggravates bleeding from necrotic areas and therefore possibly increased interest in swine biting.
Nutrition
An unbalanced diet lacking biotin, tryptophan, salt, protein or some other specific amino acids may favor tail necrosis. Excess energy and intestinal discomfort can also be contributing factors. On the other hand, excess protein associated with lack of fiber may also favor the occurrence of this condition because peristalsis and intestinal acidity decrease and this favors the growth of Gram-negative bacteria. The lack of water or its contamination also favors the occurrence. These nutritional imbalances favor the increase in the production of microbial degradation byproducts, such as lipopolysaccharides. The latter cause an inflammatory condition that leads to reduced blood supply. The tail and other extremities become painful, irritated and finally necrotic.
Mycotoxins
Aflatoxins, trichothecenes, ergot alkaloids and other mycotoxins in pig feed have been associated with episodes of tail necrosis and therefore need to be monitored and, when at risk, combated with adsorbent and enzyme inactivating products.
Biogenic amines, the result of protein degradation or even the decay of animal meal that may be present in the diet may generate the condition. Factors are present and acting to remove them and thus achieve this objective.
Factor | Symptoms | Detection or Corrective Action | |
|---|---|---|---|
| Toxins | Mycotoxins, for example:
| Depressed immune competent tissue. Reduction or refusal from direct neuronal depression of hypothalamic appetite nucleus, oral/dermal irritation, digestive disorders with ulceration and vomiting and bleeding visceral. | Positive for Afla, DON, T-2, HT-2, FUM, Ergot; ELISA raw materials, HPLC feed. |
| Endotoxins (lipopolysaccharides) | Agalactia, reduced piglet birth weight, piglet starvation, gangrene ears, tail, or feet | Epidemiology, signs, RT-PCR, ELISA for Gram-negative bugs | |
| Biogenic amines | Restlessness, trembling, recumbence, tachypnoea, pale mucous membranes, blue ears, shock, death, nausea, headaches, rashes and changes in blood pressure | Digestibility of proteins | |
| Environment | Overcrowding, ventilation, temperature, hygiene and rinsing, manipulating materials, mixing, fostering, hierarchy | Revise management practices | |
| Disease | Mange | Skin irritation, rubbing, ear shaking | Lesions, skin sample microscopy. Epidemiology, signs, RT-PCR, ELISA |
| Staphylococcus aureus H | Listlessness, skin reddening, vesicles, pustules, fever | ||
| Streptococcus | Depression, incoordination, paddling, opisthotonos, convulsions, nystagmus, death | ||
| Erysipelothrix rhusiopathiae | Depression, fever, stiff joints, anorexia, erythema |
Conclusion
As we can see tail necrosis, whether in young or near slaughter piglets is a picture with various explanations that go through facilities, management, nutrition and infectious agents. To mitigate their impact, it is essential to conduct a thorough and thorough investigation to detect the causitive agent(s).