Imagine your worst nightmare: a potentially devastating disease threatening your beloved horse. That's the reality many horse owners faced in November 2025 with the outbreak of Equine Herpesvirus-1 (EHV-1), and its more serious neurological form, Equine Herpes Myeloencephalopathy (EHM). While the headlines might have painted a grim picture, veterinary experts want you to know this isn't some mysterious new plague. EHV-1 is a well-understood virus, and with the right biosecurity measures, it's manageable.
To cut through the noise and get straight to the facts, we spoke with Dr. Ben Buchanan, a specialist in internal medicine and emergency/critical care at Brazos Valley Equine Hospitals in Navasota, Texas. He's here to answer your burning questions and debunk some common myths swirling around this outbreak.
HP: What's the real story behind this outbreak? How many horses are we talking about, and where have cases popped up?
BB: The Equine Disease Communication Center (EDCC) is your go-to source for the most up-to-date official numbers. But here's where it gets controversial... there's often a delay between a horse getting infected and that case being officially reported. So, while the EDCC is reliable, it might not always reflect the absolute latest situation on the ground. The Texas Veterinary Medical Diagnostic Laboratory also tracks positive cases within the state.
Now, about those alarming rumors you might have heard – reports of 25+ horse deaths and 200 exposed animals circulating online? Those figures are inaccurate. The outbreak was initially linked to a show in Waco, Texas, with around 1,000 horses, mostly from Texas. Before the first case was identified, some of these horses had attended other events, potentially spreading the virus further.
HP: How does EHV-1 typically spread, and what does that tell us about how it might have spread in this particular outbreak?
BB: Think of EHV-1 as spreading through horse "coughs" and "sneezes". More technically, it's transmitted through mucus droplets. This means it can spread through direct contact between horses, shared water sources (buckets and hoses), or even on items that have touched a horse's mouth or nose, like lead ropes and bits. And this is the part most people miss... humans can also unknowingly spread the virus if they've been in contact with an infected horse.
EHV can be surprisingly resilient. In ideal conditions within water, it can survive for up to two weeks! Outside of water, it can remain infectious in the environment for up to two days.
HP: What biosecurity measures are veterinarians recommending for barns, especially in affected or neighboring areas?
BB: The golden rule: minimize mucus exchange between horses. Aim for at least 30 feet between your horse and any unfamiliar horses. Ideally, 60 feet is even safer. Never share equipment between barns or between infected and non-infected horses. And, a simple but crucial step: practice good hygiene, like frequent hand washing.
For quarantine, authorities generally recommend a period of 21-28 days. This allows enough time for a full viral life cycle to play out in an infected horse. The only way to confirm if your horse has the virus is through testing. As an example, the state of Texas initially placed a 21-day hold on horses that attended the WPRA event in Waco, requiring them to stay on their home farms. If these horses didn't develop any fever, respiratory issues, or neurological signs during that period, they were cleared. But, if more horses start showing symptoms, that timeline could be extended or a full quarantine implemented.
HP: Is there anything unusual about this outbreak compared to past EHV-1 cases? Is it a new, deadlier strain?
BB: Absolutely not. There's nothing new or inherently more deadly about this specific strain. There are nine different types of equine herpesviruses. This outbreak is caused by EHV-1, and there are variations within EHV-1 itself. The difference between a neuropathic (neurological) and a non-neuropathic strain can be as small as a single amino acid change. But, all forms of EHV-1 can cause respiratory, neurological, and reproductive problems. EHV-1 is most commonly shed during fall, winter, and spring – which explains why we often see outbreaks during these seasons.
HP: What are some of the biggest misconceptions you're seeing, and what does the science say in response?
BB: The biggest problem is the panic that spreads like wildfire online. Veterinarians have a solid understanding of EHV-1, how outbreaks occur, and how to manage them. The best thing horse owners can do is follow their veterinarian's guidance. The truth is, EHV-1 isn't a death sentence. Most horses recover, especially if they've been vaccinated. Even if a vaccinated horse becomes infected, the vaccine helps reduce the amount of virus circulating in their body and lessens viral shedding, which reduces the risk to other horses. For example, during a large outbreak in 2011, there were over 400 exposed horses, and only 13 died.
HP: What immediate steps can barns take to keep things running smoothly while limiting the spread?
BB: Isolate any sick horses immediately. Avoid any mixing of exposed and non-exposed horses, and that includes sharing tack and water. Implement strict biosecurity protocols, and monitor your horses' rectal temperatures regularly.
HP: How long does it usually take for an EHV-1 outbreak to resolve, and what are the key indicators that vets look for to declare it contained?
BB: The decision of when an outbreak is contained or resolved rests with state and federal regulatory veterinarians. The 21-day hold protocol is implemented to gather information about the disease's spread and to guide veterinarians and horse owners on the next steps.
HP: What's your final message to horse owners feeling anxious and overwhelmed by conflicting information?
BB: Monitor your horse daily, and take their temperature frequently. If your horse isn't showing any signs of infection, there's likely no need to test them for EHV-1. If your horse has been exposed, quarantine them and contact your veterinarian for specific guidance.
Here's something to consider... Should testing be more widespread even in the absence of symptoms? Isn't it better to know for sure? But here's where it gets controversial... Widespread testing can create its own set of problems, like false positives and unnecessary stress.
Editor’s note: For more details about testing horses for EHV-1, see this post from Dr. Buchanan: [Link to Facebook Post]
So, what do you think? Is the current approach to EHV-1 outbreaks sufficient, or could we be doing more? Share your thoughts and experiences in the comments below!
