Question: Some of my pigs’ ears are turning blue and then they die. What are the possible causes?
Answer:
We often receive calls from producers seeking further information about sick pigs that have clear signs of “blue ears” and/or pigs that have already died from blue ears. Any infectious condition that causes severe fever can cause discoloration of the skin in pigs. The ears first turn red (inflammation) and then later blue (anoxia – lack of oxygen).
It is not only the ears that are affected, but often also the abdomen and the inner thighs. The common post-mortem lesion is blue ears. In South Africa there are several diseases that show the same symptoms – discoloration of the skin and especially the ears. We think of pneumonia, diamondback disease and various viral infections. One of our most feared diseases is African swine fever and animals that die of this disease often have blue ears. Of course, with careful and informed post-mortem examinations, the different diseases can be distinguished. Classical swine fever or hog cholera, also called classical swine fever, has very similar symptoms to African swine fever.
The disease does not occur in South Africa. It broke out years ago in the Western and Eastern Cape and the positive herds were then culled with great difficulty and the disease was thus destroyed or eradicated. The source of infection was ship waste that entered the food chain illegally. Certain pork producers are applying to the State to register their herds as state-certified compartments.
These producers test their herds twice a year for the absence of so-called exotic diseases. These are also diseases that are important in international trade. The diseases are CSF (classical swine fever), FMD (foot and mouth disease), ASF (African swine fever) and PRRS (porcine respiratory and reproductive syndrome).
The latter is also known colloquially as Blue Ear Disease. PRRS is also not currently present in South Africa and, like CSF, was diagnosed and eradicated years ago. The problem with illegal ship waste entering the food chain was also the reason for the outbreaks. Good biosecurity remains the key to healthy national pig herds. Access of people and pigs and vehicles and feed to farms must be controlled and limited. Treatment and prevention should be discussed with your veterinarian after the cause of the blue ears has been confirmed.
For further information, contact Dr Pieter Grimbeek at pigvet@agrifarmacysa.co.za.
More advice: Vet’s Advice to Farmers is a useful A5-sized manual with contributions by veterinarians published in Farming SA. Readers’ questions were answered by Dr Danie Odendaal (livestock), Prof. Gareth Bath (small stock), Dr Mary-Louise Penrith (pigs), and Dr Mick Versfeld (pigs) and compiled in this useful booklet. It contains more than 100 questions and answers. The book is available here.
Also read:
Pork production: Watering your pigs
How pigs and chickens complete the regenerative cycle at Tlhokomela Mobu Farm
From 4 gifted pigs to a thriving production: Tau Leolo’s success story
A pig farmer says: This is how pigs grow on pasture
