Tuesdays with Tony

Some of my more woke readers may have read about a horse with coronavirus this week in Arizona, as reported by Equine Disease Communications Center (EDCC). If you don’t know what EDCC is, I highly recommend checking out equinediseasecc.org for a good trip down a rabbit hole of equine infectious diseases. This site is full of great information, and up-to-date outbreak information, but I digress, as usual. 

Back to horses and coronavirus. The most important thing to know here is: Don’t Panic. Horses have their own version of coronavirus, as most critters do, and this one isn’t the same as the one filling your news feed with apocalyptic dread on a minute-by-minute basis. There are some coronavirus concerns for horses, but for the most part this virus makes a horse feel crummy for a few days, then off they go, back to normal life. 

Where did it come from?

Like most fun infectious diseases, with the notable exception in horses of the encephalitides, coronavirus comes from other horses, and usually other horses at horse shows. This is why I’m committed to my place on the counter watching the world go by with no strange cats, other than Teenie, to share cooties with me. Coronavirus gets a little interesting in what we don’t know about it. We don’t know how long horses carry this bad boy around once infected. Smart epidemiologists think around three weeks, based on statistical analysis. The smart scientists also aren’t sure how long this virus will survive in the wild. Other versions of the coronavirus, like the ones cows carry, live around 2 weeks in water, and a little longer in manure. 

In the continuing realm of things we don’t know about this virus, no one knows if there are carrier horses. These are horses who don’t display any symptoms, but do shed the virus. The humans are looking less and less smart when it comes to this virus. What do they know? It’s more common in winter, probably because the virus survives in the wild better in colder temperatures, but again, that’s a guess based on other coronaviruses. 

What does an infected horse look like?

This is where coronavirus infections really get interesting. Most viruses cause symptoms in one area of the body, like a runny nose, or diarrhea. Coronavirus causes respiratory and GI symptoms, sometimes all at the same time, sometimes not. It does cause a fever, and typically a pretty darn good one, up on the 104-105F range. From there, it depends on the horse; some get cowpie-type manure, others get blowing diarrhea, some get respiratory signs, some get none. 

A common symptom in horses with GI signs is hyperammonemia. What the heck does that word even mean? Hyperammonemia is too much ammonia in the blood. This can happen with any GI upset in a horse, but my Docs more commonly see it in horses with diarrhea. It occurs when the bacteria in the gut get very, very mad, and start producing ammonia. Ammonia is very quickly and easily absorbed into the bloodstream, where it heads to the brain. In the brain, it causes the connections to go a little wonky. These horses will act neurologic, often stumbling around a stall or paddock, and showing inappropriate interactions with the environment. They will overreact to sounds, but not react to their owner dumping food for them, or talking to them. Luckily, this usually goes away pretty quickly once the GI tract recovers. The respiratory signs are pretty typical cold signs: some nasal discharge, coughing, runny eyes. Nothing too special.

How do you know if you’ve got Coronavirus?

You test the poop.  That’s right. We take a small sample of poop, and that gets tested for coronavirus DNA; well RNA because it’s an RNA virus, but that’s getting super geeky on you. My Docs will definitely recommend testing if your horse recently returned from a horse show, gets a fever, and a bellyache. It’s very unusual for colicky horses to have fevers. This means a fever plus a bellyache equals a high suspicion for coronavirus.

Make it Go Away

Luckily, nearly all horses infected with coronavirus (much like people) will slay this dragon on their own. Being a virus, antibiotics won’t help, and might even mess up the normal GI bugs, leading to bigger problems. The best way to help these horses heal quickly is to give anti-inflammatories, keep the horses on a good diet, and keep them as happy as possible. Horses will start showing signs very quickly after they’ve been exposed, like 2-3 days quick, then take about a week to get better. 

Coronavirus is a buzzword right now for you humans. The best way to handle it, human or horse, is to practice good biosecurity. Try hard to keep your horse from touching noses with other horses when you are out showing or trail riding. You never know where that other horse has been. Isolate new horses that come to your house for at least 21 days. And do this cat a big favor: Don’t share water buckets or drink from community water troughs. That’s just plain nasty!

Until next week,

~Tony