Prevention is key to combatting ‘special’ swine disease
Minus the curse words, pig producers usually describe swine dysentery as an expensive, persistent and difficult-to-manage disease. But “special”? Why would anyone use the word “special” to characterize this contagious bacterial disease?
By Suzana Cortiano Stubert
“What makes it ‘special’ is that it needs the right gut environment to multiply, and once it does, it damages the [pig’s] large intestine in a way that causes the classic bloody, mucoid diarrhea,” explains Dr. Ygor de Paula (DVM, PhD), a veterinarian and postdoctoral fellow at the University of Saskatchewan (USask).
De Paula is part of a research team led by Dr. Matheus Costa, a swine medicine specialist based at the Western College of Veterinary Medicine (WCVM).
“For producers, it's extremely frustrating because outbreaks cause feed inefficiency, mortality, extra labour, treatment costs, and sometimes long-term production setbacks. In short, it’s a disease that’s expensive, persistent and difficult to manage,” said de Paula.
A pig affected by swine dysentery usually shows a reduced interest in food and weight loss. It moves less in its pen and spends more time lying down. In addition, there’s the disease’s classic sign of diarrhea, which starts as liquid and progresses to a mucoid-bloody consistency. It’s clear that they are sick, as they don’t display the typical behaviour of a healthy, curious pig.
Brachyspira hyodysenteriae, a spirochete (bacterium shaped like a screw), is one of the disease agents that causes swine dysentery. This pathogen causes severe colitis, an inflammation in the large intestine that makes the organ red and painful inside, which quickly affects the pigs’ ability to gain weight.
Swine dysentery hits producers directly in the pocket. Among all swine diseases, it stands out because it spreads fast, it’s difficult to eliminate from a farm, and there’s no commercial vaccine available in North America. On top of that, with the global pressure to reduce antibiotics, treating swine dysentery has become even more challenging.
What can producers and veterinarians to combat this disease? Prevention becomes key.
“If I were to enter a barn dealing with this issue today, I would focus on eliminating risk factors by ensuring thorough cleaning and disinfection of the facilities, reinforcing biosecurity measures and closely monitoring the animals,” said de Paula.
“Combining these practices with targeted antimicrobial treatment is currently the most effective approach to manage an outbreak.”
De Paula also highlights that the WCVM research team is developing research projects focused on non-antibiotic strategies to combat swine dysentery. Since antibiotic treatment is often the primary response during outbreaks, they’re exploring alternative approaches aimed at modifying the intestinal environment to make it less favourable for B. hyodysenteriae to establish and proliferate.
These alternatives include a new drug that focuses on the bacterial mechanism of causing inflammation, different diet compositions and specific organisms that can be used as probiotics.
From a research perspective, de Paula says that swine dysentery is particularly compelling because of the lack of available commercial vaccines. This gap represents a significant opportunity to develop innovative solutions with a meaningful impact on veterinary science and swine health worldwide.
Preventing swine dysentery would not only improve animal health and welfare but also help reduce the substantial economic losses faced by producers, ultimately benefiting both pigs and those who raise them.
Suzana Cortiano Stubert of Brazil is a USask PhD student based at the Western College of Veterinary Medicine (WCVM). Her graduate supervisor is Dr. Matheus Costa in the WCVM’s Department of Large Animal Clinical Sciences.
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