Most swine producers know that pig ear necrosis can be a concern in their herds.
But the condition which has existed in herds around the world for years, has not been well-understood in terms of its cause, nor in how best to deal with it.
So new research from the University of Saskatchewan (USask) which has identified the cause of pig ear necrosis is an important development for the industry.
Dr. Matheus Costa (DVM, PhD), an associate professor with USask’s Western College of Veterinary Medicine (WCVM) said pig ear necrosis isn’t the pig killer some diseases are which perhaps have a higher profile in terms of concern with producers, but it can impact pig growth and that is an economic impact.
“It’s not a super acute disease. Pigs are not going to drop dead,” said Costa. “But they don’t grow as they should.”
It’s no wonder as pig ear necrosis is a painful and troublesome affliction that causes the ear tissue of pigs to rot away.
Costa told Prairie Hog Country that if anyone has had a frozen digit they are aware how painful it is.
“A frostbite, the way people explain it, it’s excruciating pain,” said Costa.
So it is reasonable to assume pigs suffer the same pain from necrosis, and that is likely to limit interest in food, and thus growth, he offered.
The infection is painful, affects growth and meat production, and often leads to injudicious use of antibiotics.
Costa said producers might never see the most severe cases “where ears are lost,” but “ear tip necrosis . . . is frequently there.”
In fact, the condition exists widely enough in Western Canada that the industry helped fund the research Costa and his team undertook. He added it is estimated the condition exists “in at least 50 per cent of barns . . . It’s out there.”
That does not make Western Canada unique. Costa said it exists in herds from China to Brazil, basically everywhere pigs are raised the condition exists.
Pig ear necrosis was described in the 1960s, but it has been nearly impossible to identify what causes it.
Costa said the condition causes a pig’s ear tissue to “necrotize,” or progressively rot. It is painful and damaging for the pigs, causing lesions and affecting their growth and profits for producers.
“It was previously described as a multifactorial disease, likely because we didn’t know what was causing it,” Costa said in a Usask release. “We kept seeing it, it was always there, everyone talked about it … and obviously the pigs suffer . . .
“It’s not the showy new disease everybody is freaking out about, but it is costing everybody a chunk of money.”
Now thanks to the Usask research there is at least a foundation established to better address the condition in future research.
That first step is identifying the cause.
Through clinical research – some seven years of effort — at USask, Costa and his team identified the cause is actually a common bacteria called Fusobacterium necrophorum found in the gastrointestinal tract of many mammals, including humans.
Pig ear necrosis only occurs when the bacteria are transferred via saliva through biting or chewing ears, an identified habit of pigs, detailed a Usask release. Costa and his team were able to confirm their findings in a lab setting, and their research was recently published in the scientific journal PLOS One. Their research received support from Saskatchewan’s Ministry of Agriculture and numerous members of the Western Canadian swine industry.
Costa said identifying that ear biting is how the condition is spread suggests producers may be able to lessen the occurrence of pig ear necrosis by addressing ear biting.
In some cases ear biting may be a response to boredom.
Costa said a simple way to address boredom is to give pigs something else to ‘play’ with.
“A 2X4 has been found to enrich their play time,” said Costa.
“Straw is another great option,” but Costa said he does appreciate that does not work in all manure handling systems.
An ear biter may also just be a ‘bully’ pig, noted Costa, adding in that situation removing the offending pig from the pen may be the best option.
Moving forward vaccination maybe the best option.
After identifying the cause as an opportunistic bacteria, researchers have been able to develop a vaccine to protect against pig ear necrosis.
Because the causative bacteria are so prevalent, Costa said removing it completely from pigs would be unrealistic. Instead, by using a research vaccine developed at USask, Costa said they were able to reduce the clinical signs of pig ear necrosis by approximately 50 per cent. With the help of USask’s Innovation Mobilization and Partnerships office, a patent application for the vaccine has already been filed, noted the Usask release.
Costa told PHC that producers may not rush to vaccinate specifically for the condition, but he sees more interest being generated by combining the new vaccine with others where protection against the losses of pig ear necrosis comes with that single shot. •
— By Calvin Daniels