A New Threat Emerges: Understanding Equine Polyneuropathy in Iceland
The equestrian world is facing a sobering reminder of how much we still don’t understand about horse health. For the first time ever, Iceland has confirmed cases of equine polyneuropathy (AEP)—a mysterious and devastating disease that has plagued Nordic countries since 1995. Tragically, 13 horses have already lost their lives to this mysterious ailment, and veterinary experts are scrambling to understand how and why it appeared on Icelandic soil.
What Is Scandinavian Knuckling Syndrome?
Also known as Scandinavian knuckling syndrome, AEP presents a heartbreaking set of symptoms. Affected horses experience progressive muscle weakness in their hindquarters, which can cause their fetlock joints to knuckle forward—hence the disease’s distinctive name. What makes this condition particularly puzzling is that horses remain fully conscious, maintain a healthy appetite, and exhibit normal behavior despite their deteriorating physical condition.
Despite nearly three decades of research since its first appearance in Scandinavia, the root cause of AEP remains unknown. This lack of understanding makes prevention and treatment incredibly challenging for horse owners and veterinarians alike.
The Feed Connection: What We Know So Far
One crucial clue has emerged from the Iceland outbreak. According to SigrÃður Björnsdóttir, a veterinary officer for horse health and welfare at MAST (the Icelandic Food and Veterinary Authority), all 13 affected horses shared something in common: they had all been fed hay from the same field.
“All affected animals had been fed with hay from the same field, although not all horses who ate the hay showed symptoms,” Björnsdóttir explained. This finding suggests that while contaminated feed may play a role in triggering AEP, other factors—possibly genetic predisposition or individual susceptibility—determine whether a horse develops the disease.
Containing the Crisis and Looking Ahead
The good news is that AEP has not been detected on any other Icelandic farms. As of the time of this outbreak, MAST noted that the risk of discovering additional cases would likely be low, as most young horses had moved to pasture grazing and away from potentially contaminated stored hay.
However, veterinary authorities aren’t taking chances. MAST has issued a formal request for all suspected or confirmed cases of AEP to be reported immediately. This vigilant approach is essential for tracking the disease and preventing its spread.
The International Question: Will AEP Go Global?
As horse lovers and industry professionals, we must consider an uncomfortable question: could this disease spread beyond Nordic countries? The emergence of AEP in Iceland—a country that hadn’t seen the disease before—demonstrates that geographical isolation is no guarantee of protection.
Feed quality and sourcing are critical. Horse owners worldwide should prioritize stringent controls on hay and grain suppliers, ensuring that feed is tested and sourced from reputable, disease-free sources. Given that contaminated hay appears to be a vector for AEP transmission, maintaining high standards for equine nutrition isn’t just about performance—it’s about survival.
What Horse Owners Should Do Now
While the risk remains relatively contained, this outbreak serves as a powerful reminder for the entire equestrian community:
- Know your hay supplier: Build relationships with trusted hay producers and request testing when possible.
- Monitor your horses: Watch for signs of unexplained hindquarter weakness or knuckling in the fetlock joints.
- Report concerns: Contact your veterinarian and local animal health authorities if you suspect AEP.
- Stay informed: Keep up with equine health alerts and research developments.
The appearance of equine polyneuropathy in Iceland is a wake-up call for the global horse community. While we hope this mysterious disease remains contained to Nordic regions, we must remain vigilant and committed to understanding its origins. Until we solve the puzzle of what causes AEP, our best defense is careful management, quality feed sourcing, and open communication among veterinary professionals worldwide.
The health of our beloved horses depends on it.