Rotavirus

When I got a text from my friend saying “the results are in.  Rotavirus.  Call me for more info.” I’m pretty sure I called her before her finger left the phone after hitting send.  She wasn’t surprised.  It was baffling to me, and apparently to the internal medicine specialist vet at the clinic, as he called the lab to ask them to double check the tests and run it again.  They already had, as they too were baffled after seeing Indy’s age.

(For Indy’s experience and symptoms, see “Indy Calls Out Sick“)

What is so baffling about this diagnosis?  Or perhaps you are asking more basic, what is Rotavirus?  I was familiar with the disease in preparing for Indy’s arrival, but decided to do a little more digging to get all the facts.

Rotavirus is a viral infection.  It is seen in many species, including horses and humans.  In the case of equine Rotavirus, it does not have the ability to be transmitted across species, nor from human to horse.  In humans, it is very common in young children and typically by the age of 5 they have developed an immunity.

Rotavirus is the most common cause of foal diarrhea.  Over 50% of foal diarrhea is caused by Rotavirus, with some studies reporting as high as 70%.  Diarrhea can lead to dehydration, malnutrition, electrolyte imbalance, and, albeit rare, death if left untreated.

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Indy, all better, enjoying a foliage hack with Shady and I.

It is baffling that this is Indy’s diagnosis because it is nearly unheard of for a horse over the age of 6 months to get it.  Indy, at 16 months, should have developed immunity and just shed the virus from his system.  Foals ingest Rotavirus from infected feces and typically develop symptoms within 1-2 days.  Once in the system, the virus replicates in the GI tract and attaches itself to the epithelium of the villi in the small intestine.  This then disrupts the digestive process, causing decreased metabolism, absorption, and digestion.  It greatly affects water absorption, which contributes to diarrhea.  The intestine responds to the large volume of food not being digested by producing more digestive fluids, in an effort to flush the food out of the body.  This in turn overwhelms the large intestine, which is responsible for water and fluid absorption, causing more water to pass through the horse, leading to very watery diarrhea.

There is no “cure” for Rotavirus; the only option is to treat the symptoms and wait for it to pass.  Rotavirus is highly contagious as the virus replicates extremely quickly.  A single foal can shed millions of Rotavirus particles in one small particle of manure.  Prevention is key – an affected foal will shed the virus for about 10 days, with a rare possibility of them shedding the virus asymptomatically for a few months.  Rotavirus is not affected by bleach and can survive in the environment for up to 9  months.  The human strain has also been found in water sources.  Pregnant mares can be vaccinated for Rotavirus, however even those foals can still contract the disease, though the symptoms are typically more subdued.

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I hadn’t vaccinated Shady for Rotavirus but clearly she shared her healthy immune system with her son.

Treatment includes fluid treatment (IV fluids if necessary), electrolytes, probiotics (to help support the hindgut), and, in extreme cases, tubing water and nutrients directly into the stomach.

In Indy’s case, he did not have diarrhea.  He had a fever, which in turn caused him to feel lethargic, weak, and reluctant to drink.  He may have been having some digestive upset as well, which would explain why he didn’t want to drink.  Eating was only an issue when his fever was high.

Our theory is that Indy somehow came into contact with Rotavirus recently, despite not being around any young foals.  The virus doesn’t live long in the digestive system as the epithelial cells where the virus lives are always replicating, sloughing off the old ones and constantly creating new cells, so the thought that he had been harboring it for a while is unlikely.  Having a strong immune system, Indy didn’t react by getting diarrhea, but rather instead just developed a response to a virus – a fever.  There have been some cases of healthy foals who are shedding the virus, but not showing diarrhea.  I guess I can be grateful that this means Indy has a very healthy immune and digestive system, and I did pretty good to keep him from being exposed for so long!

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Happy that this kissable nose is all better!
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Indy Calls Out Sick

Indy decided to give me a bit of a scare over the past few days.  I had had a very busy weekend working and I guess he felt he needed more attention.  I had gone to the barn Saturday night and he was his normal self.  Sunday night, however, he hadn’t finished his dinner grain, quite unusual for him.  It had been pouring rain all day, remnants of Hurricane Matthew, and the horses had stayed in for the day.  Indy pawed a little and was stretching so I took him and Shady to the indoor to run around some.  Indy started off a little quiet – standing confused while his mother tore around the indoor acting like a child.  He then ran around with her some as well, kicking up his heels and getting some good energy out.  We walked for a bit to cool down and each had a thorough grooming.  Indy then finished his dinner and resumed eating his hay.  I thought perhaps he had had a little gas buildup from being stuck inside all day, not moving.

I headed to the barn mid afternoon Monday after catching up on a lot of work leftover from the weekend.  Indy had eaten his breakfast, drank, and finished his dinner hay from the night before.  Barn staff said he was quiet going out in the morning, but otherwise normal.  When I went out to get him however, he told me otherwise.

He walked up to me, sluggish, and put his lovely head into my arms.  He gave a couple sad little paws at the ground with his hoof, trying everything he could to communicate that something was wrong. Walking into the barn he was slow and kept his nose as close to in my hand as he could. He would stop and stand, taking a break, then continue after a pat.

I took his temp as soon as we were in.  104. The normal horse temp, in case you don’t know, is 99-101. 104 is terrifying to me.  Three of Indy’s hooves were quite warm to the touch.  I don’t know why the fourth one wasn’t, he must have been standing in a cool area with it or something.  I ran for the oral Banamine and, much to Indy’s dismay, squirted it down his throat.  We then slowly walked down to the clinic.  I wanted to do bloodwork as soon as possible, as it often takes a bit to get the results back.

Thankfully, I have wonderful friends that work in the clinic who were extremely supportive and quickly jumped in to help.  They drew blood to send out to a lab and also some to take a look at there in the clinic.  The good news was that his bloodwork looked normal – nothing elevated other than his SAA levels.  SAA refers to a protein which is made in the liver.  It is part of the acute line of defense, part of the first stage of response to inflammation, trauma, stress, etc.  It seemed as though we were catching something in the early stages but we weren’t sure of what yet.

While all we had for a symptom was sudden onset of fever, anaplasmosis was a likely possibility in all of our minds.  Shady had had it a year ago, from the one lousy tick I found on her all year.  She too had only exhibited a fever, with lethargy and diminished appetite as a side effect of the fever.  She had actually been able to beat it on her own, without medication, only Banamine to keep the fever at bay.  We decided to start him on Oxytetracycline to get a start in treating it.

I stayed with Indy until late night, waiting for the Banamine to kick in and for him to start feeling more comfortable. I scolded myself over and over again for not taking his temp Sunday night.  I had been so sure he just needed to move, and maybe he did.  His feet hadn’t felt warm at all, he had returned to his normal self after running around some, and was himself in the morning.  Maybe he had just been starting to have some physiological changes.

His temp dropped down to 101 and he returned to being himself.  I felt that the Banamine and Oxytet were doing their job and headed home for the night.

The next morning my friend texted me and said his temp was back up to 104. I raced to the barn and found the staff at his paddock, explaining how he “looked drunk”.  He was weak and looked tired. Looking at his stall from the night before you wouldn’t have guessed.  He had eaten his breakfast, eaten his hay, and pooped normal, though a little dry.  The only sign of worry was that he hadn’t drank as much as normal.

We headed back down to the clinic for IV Banamine and also to submit some manure for testing too.  We hung out in the clinic for most of the day, me sitting in his stall for company and to keep an eye on his food and water intake.  He found my iPad to be quite fascinating.

His temp was down and he was feeling himself by early afternoon.  It was a beautiful day outside, so I put him back out with his best bud.  He did get a drink, played some bitey face, and then napped in the sun, trying to rest his chin on Cal’s back.  I headed home for a late lunch and returned a couple hours later.

Upon coming back he was getting lethargic again.  I hoped he was just tired from a long day of battling whatever it is.  Sadly, I saw that his temp was rising again.  As much as I hated to do it, we gave him more Banamine and his dose of Oxytet.  The Banamine dosage we were using was less than full strength in an attempt to control the fever with minimal amounts.  It was back to the waiting game.

By 9pm his temp was down to 101.3.  He was eating well, still not drinking a lot, and laying down to rest often.  I actually had given him his dinner “in bed” so to speak, as he was laying peacefully but really wanted to eat. Some people would have said not to feed him, but he was passing manure normally and I thought it best to keep his strength up.  His hay is always soaked and I soaked his chopped alfalfa to at least get some more water in him.

I left him to rest while I had dinner and showered.  At 11:30pm I got a call from the woman doing night check that his temp was up again to 104 and he was cold.  I grabbed some warm clothes and headed back, for what I knew would be a long night.  Driving up I began to get really worried; why wasn’t the Banamine keeping the fever down longer? Why has the Oxytet not kicked in? What is wrong with my boy???

One of the interns met me at the barn and we gave Indy a different antipyretic that isn’t an NSAID and has less negative effects on the GI tract.  It would take a little longer, but hopefully last longer and be more gentle.  It was a little too soon to give him more Banamine anyway, and it clearly was not helping too much!

I settle into my chair with his door partially open so we could see each other and chat.  He would poke his head out and see what TV show I was watching or try to help me write an email.  He would lay down, nap, get up, eat, and repeat.  While he was definitely uncomfortable, he wasn’t acting colicky or as if in a lot of pain.  I resisted the urge to check his temp every five minutes and resorted to feeling his feet.  Those are a pretty good indicator of his temp.

Maybe it was the exhaustion, or perhaps the cold, or maybe it really happened.  Whatever it was, at about 4am Indy looked at me and I knew it was over. I swear he got up, looked me in the eye, sighed contentedly and said “it’s over, I’m good, you can go home and rest now.” His temp was creeping down, then at 102.8. Still high, but it finally was breaking.  He got a drink, turned to eat, and dismissed me with a swish of his tail.  I went home feeling relieved and safe.

I awoke to a text from my friends saying that it had taken two of them to take my “wild” horse’s temp.  He wasn’t being too naughty, rather just politely saying “you can stay out of my bum now, thanks.” His temp was down to 100.3 and he was himself.

Since that 4am moment he has returned to normal, with a low temp, good appetite, and he is back to being a good drinker.  Of course, now that it is over, we got the lab results back.  Before I share the diagnosis, I would love to hear what you think it could have been, based on our experience.  My next blog post will be all about the disease!

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Back to normal