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Equine Diseases

Course video 39 of 49

The topics this week will focus on equine health. Monitoring and taking care of your animal’s health is critical to owning any equid. We will start off with the normal equine vital signs and then we will discuss administering first aid to your animals. We will then cover the different parasites and diseases that can afflict these animals. Finally, we will end the week discussing some common genetic disorders.

There are over 100 million horses, donkeys and mules in the world today and owners of these animals can be found on almost every continent and in almost every society. The Horse Course will cover many unique aspects of equine ownership and touch upon the science behind many of today’s management practices.

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Disease Management, Nutrition, Animal Behavior, Vital Signs

教学方

Chris J. Mortensen, Ph.D.
Professor

脚本

All right, so in the next lecture, we're gonna cover [COUGH] equine diseases.

And I'm gonna start this lecture with kind of a scary situation that happened

a few years ago in Australia and for

those that aren't aware, there was a major equine flu outbreak.

And the eastern portion of Australia that really caught my attention,

especially as a researcher and

an equine enthusiast, that really was kind of a scary situation.

What happened was in 2007 four racing stallions from Japan were shipped

to Australia and they had been exposed to equine flu In Japan.

So they are actually infected, and they carry the disease to Australia.

And our friends down under clearly will probably remember this,

because it quickly spread, rapidly spread to many other horses,

and the eastern portion of Australia was under quarantine.

And within a few weeks or just within

a matter of a couple weeks there was over 400 horses on 50 properties.

So you started with four horses and

all a the sudden you have hundreds of horses infected.

All over the southeastern portion or the eastern portion of Australia,

and at the height of the epidemic there was

over 47,000 horses infected on almost 6,000 properties.

So this disease spread relatively quickly and

this graph is going to show you how quickly that disease spreads.

So within four weeks, the epidemic peaked, so

you can see right there, the peak of it.

But within a month, thousands of horses had been infected.

Now the very positive thing about this outbreak is, equine flu,

similar to human flu, is not very deadly.

It is only really dangerous in the really young horses or young foals and

then the older aged animals.

So similar to human population.

They're not as a deadly disease.

But what was scary about this is if it was a deadly disease,

it could have wiped out many, many horses.

So, something that just really was like wow,

showing you how these diseases can be really scary.

Now one that is particularly scary here in the United States,

is West Nile Virus and in the last decade, we have heard,

here in America about the spread of West Nile and even infecting dogs and people.

But, what's really concerning about this diseases is about 40% fatal on horses,

so four out of ten horses infected will die from this.

And this disease reared it's ugly head in 1999 in the northeastern

portion of the United States.

So it started, the epicenter, was in New York.

And within a matter of four, really five years,

it had spread all the way across the United States.

And at that time, when it was spreading, I was here in California.

And each year roughly there on the central coast, and

each year we were, we vaccinate this year or do we wait till next year,

because you know that disease we had seen it march across the country.

So again being very aware of current events and

where equine diseases are really

relevant at the time as it behooves you as an owner to pay attention to this.

Now, here's a list of the diseases we're gonna cover in this lecture, kinda

break them down found by respiratory, neurological and then some of the others.

So we'll go into each of these but obviously this isn't a complete list.

Now had talked about equine flu, it's a highly virulent

virus viral disease that effects horses.

The symptoms are very, very similar to what we would experience with flu.

You get a spike in temperature and fever.

Now, remember normal temperature for a horse is 100 degrees Fahrenheit,

38.5 degrees Celsius, roughly that for horse.

So 106 for us is the death zone,

106 for horses is quite hot but not quite the death zone just yet.

So obviously they are not gonna want to eat, they might be coughing and

get some discharge from the eyes.

Now to prevent this you actually can vaccinate for and obviously is one of

the recommended vaccines because we don't want to spread this disease and then also

you want to do is isolate your animal so really quickly I'll just talk about that.

Talking about you'll hear it in the animal sciences, we hear this term, biosecurity.

So on your property or with your animals, you want good biosecurity.

What that means is that you're trying to limit the spread of the bugs,

the parasites, and then also diseases.

So one of those is if you do have a new animal coming to your property, you want

to isolate them and keep them away from your other animals for at least 30 days.

And you want to monitor them and make sure they're healthy and make sure they do have

a health check by either an animal health specialist or a veterinarian.

So that's one good bio-security measure you should take on your property.

Now the next disease is called Equine Herpes Virus.

And theres five forms of this.

The two that we are mainly concerned with, the EHV 1 and EHV 4.

These are the two that are, you know, really dangerous with the equites,

and it's because they, they not only can induce abortions, so

your Jenny's and your mares can abort if they infected with this.

But it's also a neurological disease.

So, it can cause a lot of uncoordination and further problems.

Now, EHV3, that's an STD or sexually transmitted disease.

So, if they are infected with that, obviously, you're gonna have trouble

breeding them and it's not something you wanna spread or infect other animals.

Now EHV-1 has been in the news a lot here in the United States lately

because we've had some major outbreaks.

In the country and one of the more recent ones and

I know this was still a few years ago but its worth mentioning was in 2006,

15 infected horses came to the United States from Germany.

And they had spread out to different states a lot of them came to Florida here,

but they did go to other states for some competition and training and

so they infected other horses and it was a major outbreak and

it actually shut down a couple of our veterinary schools here in

the United States that had infected horses.

They were under quarantine for some time and was kind of a concerning situation.

Now in my own backyard here in Central Florida.

Last summer we had an outbreak at a major horse show, it's called HITS,

here in the central part of the state, and there had been some show horses that came

in and they were infected and it actually affected a lot of other horses and

exposed them to the EHV-1 A virus.

So this is a disease that affects horses around the world.

And really it's these horses that travel that go to shows, or

they go to the racetrack.

These are the ones that are really at risk of contacting this disease,

obviously that's how it spread.

So, it's spread by horse to horse contact or contaminated equipment, hands.

If you went up and touched a horse that was infected and then went and

touched your own horse you could potentially spread that disease.

If these horses are using a common water source,

say they have a big bucket of water or a big tub of water outside the show pen and

an infected horse goes and drinks out of it and then your horse goes and

drinks out of it, your horse just was exposed to this disease.

So we'll talk about some of the preventive measures To limit that.

So some of the signs that you would see, again, not quite high of fever as you'd

see in the flu, but still their temperature spikes.

They're gonna have some nasal discharge, they're gonna cough.

And then they have these neurological symptoms where they're uncoordinated,

they appear weak.

You can tell something's not right with them.

So, vaccination.

You can vaccinate for these diseases and we commonly do.

And then going back to traveling to horse shows and good bio security measures.

We say practice good horsemanship or horsewomanship, where

not only do you clean your hands, clean your equipment.

You don't allow your horse to drink from that common water source.

They have their own bucket that only they drink out of.

You don't share equipment with unknown horses, and you don't go and

touch unknown horses and then go and touch another one and touch yours.

Which I've been guilty of in the past.

I always like to pet horses and pat them on the neck and stuff.

And that's bad horsemanship.

I shouldn't be doing that because you can spread disease that way.

So just be aware of it.

Now this next disease is awful.

If you've ever dealt with it, the good thing is it's not very fatal in horses.

It's just a nasty one you have to deal with.

And it's called Strangles.

And it's a bacterial disease, and it's very, very contagious.

And I've had one of the farms I've worked on where

we had a number of horses get infected off one horse.

And so the clinical signs, again,

you're gonna see a spike in temperature and really what you see what strangles is

are the swollen glands especially around the neck or throat latched region.

So that's where this horse right here, this is all of the infection.

It's swollen and the body's fighting their bacteria.

And they'll have some discharge and obviously they're going to lethargic and

depressed because this is not a fun thing for horses to have.

So, how do you prevent strangles?

You can vaccinate for it.

You want to practice good hygiene and

isolate new animals to your facility or infected animals.

The facility I was working on, it was a breeding farm,

brought in a mare that had strangles, and she spread it to our entire farm.

Because we had not, at that time, had good biosecurity measures.

So it's really kind of a nasty,

you have to lance those swollen glands and drain them.

It's just not fun to deal with, and not fun fun for the horse obviously.

Now, back to our last lecture, we talked about external parasites and

it's worthwhile here to mention, these nasty mosquitos, ugh, can't stand them.

And, the spread of mosquitos.

And I put this up here to show you that, yes, the climate's changing and

the majority of climate scientists agree the earth is warming up.

We won't discuss how or why or anything like that.

But what it does mean is, as the environment changes, as it gets warmer

over the next 50 years, mosquitoes are gonna spread to a wider range of areas.

So just be aware of that because mosquitoes are just a terrible insect that

carries lots of diseases, I don't know even why they're here.

But they do serve some purpose in nature, I just don't know what.

So, talking about the next disease that's spread by mosquitoes

is equine encephalomyelitis.

Or what we call sleeping sickness.

Now, good old mosquitos are the ones that transmit it.

And this virus is carried by birds and

also rodents, as you can see in this transmission cycle.

So, here's birds and here's rodents.

Well, the mosquito comes, bites them, gets the virus,

and then turns around and then will bite your horse.

Or even us which is, ugh, even worse.

Okay.

So when it does that, it spreads this virus, and

that's how the transmission cycle, or what it looks like.

Now this is a disease that is neurological so

it attacks the nervous system, and what's really awful about these diseases is

it has a high mortality rate, so horses tend to perish due to this disease.

Now here's three major strains of The encephalomyelitises.

And there's a Western, a Venezuelan, and an Eastern.

There are some other strains too.

They're primarily isolated in North and South America but today, you know,

horses are transported around the world to compete, to breed, for whatever reason.

So I've seen some papers where this disease has popped up in

Europe with some horses and other parts of the world.

So you have to be aware of it

if you don't live in the Americas outside of our own region.

So with this disease, obviously, vaccination is one way to prevent it.

Here's a horse afflicted with encephalomyelitis.

Some of the clinical signs, they're gonna have a fever, like the other diseases.

They're gonna be hypersensitive, so to light and to movement.

Because again, this is a nervous disease, it can lead to paralysis and death.

So not fun to deal with, but again,

why you want to vaccinate your animal to prevent the spread of this disease.

All right, so we've already talked about West Nile virus, and again, very similar

to the other encephalomyelitises, this one's particularly spread by birds.

So like I said earlier, I was on the West Coast of the United States, and

we'd seen this disease march across the country and

birds were the ones that were spreading it.

So the birds are infected,

the mosquito bites the bird, then the bird in turn bites the horse or bites you.

That's how people get it, it bites the dog, that's how dogs have gotten it.

And again, that wonderful mosquito bug that is spreading this disease.

So West Nile virus effects almost every continent on earth.

So again another neurological disease, so gonna be very similar to the others.

They're gonna be depressed, lethargic, they are not gonna want to eat.

They'll have a fever, they're gonna be weak.

Can be some paralysis, but the good news is there are vaccines available.

Check with your region of the world to see if they are available where you're at.

And you should vaccinate for West Nile Virus each year.

Okay, so the next one is EPM or this is a equine protozoal.

Protozoal myeloencephalitis, so again a neurological disease and

primarily carried by possums but there are other reservoir animals you can see here.

Cats and skunks and otters they can also carry this wonderful protozoa.

So again, it's a disease that's worldwide and

typically these animals that are infected will

defecate near food or in water of our horses.

And then our horses come by and eat and they get some of the feces in their

feed with the protozoa, and that's how they ingest it.

So not a fun bug.

Now, again, it's neurological, so everything we've talked about to this

point, it's gonna be very similar, the lameness, the lethargy,

they're gonna be depressed, not gonna wanna eat, stuff like that.

And can show a little bit of lameness, too, where they're not walking well.

So as far as preventative measures, check with your region of the world.

Here in the United States there's a new vaccine in development that's

coming on the market, so that may be a possible One to give your horses,

but you have to check with you veterinarian.

Now, here's some easily preventable diseases, and

one of the first ones is tetanus.

And tetanus is associated with anything with a rusty fence, rusty nails,

any kinda rusty metal, is where this originates.

So, a horse or donkey will come around, get a puncture wound,

get some of this tetanus in them, and then they develop this disease.

So this is a worldwide concern disease, and it has a really high mortality rate,

80%, but can be easily preventive with a vaccine.

So some of these systems that you'll see is this saw horse stance, and this is what

you see with this animal right here, because their muscles are tightened up.

And they get something also called lockjaw.

Where their jaw muscles lock in place and they can't really open their mandible.

So, they can't really chew or eat or anything, and stumbling.

Some of the things you'll see with this but

again very easily prevented with an annual vaccine.

Now the next more easily prevented disease is rabies.

And here's a worldwide map of where rabies exists.

And rabies is everywhere.

Here in the Americas, even though it says it is low,

its still there in the environment.

We still need to prevent its infection.

But if you're in the areas of red,

I'd most definitely this is something you wanna vaccinate your horses or

donkeys against if you can because this is a 100% fatal disease if they get it.

And an infected animal will either bite or

scratch an equid, and then that's how it's spread.

So if your horse does come down with this or

your equid comes down with this, it's 100% fatal.

There's no way to bring him back from this.

So, there's gonna be different clinical signs.

Here's one that we always associate with our dogs, with

the foamy mouth but it's gonna be similar to the other neurological diseases.

The animal's gonna be really depressed and lethargic and all those things.

So you can prevent this with vaccination.

Now the final one I just kinda threw it up there on one big slide

is Equine infectious anemia.

And this is one that we've been fighting, trying to eradicate.

And it's pretty much eradicated in the United States, but

there are horses that still come up with this.

So this is a viral disease that attacks the immune system.

And pretty much reduces that animal's immune system.

So if you've ever traveled and you've had to get this thing called a Coggin's test,

that's what this is looking for because it is highly virulent,

it's easily transmitted.

Now the laws of requiring a Coggin's test is gonna be different for

a country and even in the United States by state-by-state.

But any time, really any time you travel with your animal.

If you're going to travel to shows or anywhere else, generally you're gonna need

some sort of Coggin's test to prove that they're EIA negative.

But if your horse or

animal is positive for EIA, you definitely want to segregate them.

Keep them away from other equids.

And generally most people will euthanize the animal

to prevent the spread of this disease.

So in some countries there might be a vaccine available, so

you can check to see if you do.

Cuz again, those horses that travel,

they're the ones that are really at risk for contracting any of these diseases.

All right, so this is a huge slide, and I'm gonna step here,

because I knew this slide would be big.

But I wanted to throw out some other diseases that are seen around the world.

And obviously there's more than this, but these are some of the other big ones.

And you can see where they're actually,

what part of the region of the world that they afflict.

And one that's really kind of scary is called this Hendra Virus.

And really they see it in Australia but there's some different forms,

and Asia, particularly southeast Asia.

And this is a disease that is 60% fatal in horses.

And what's even more scary is you can get it from your infected animal,

and it has a 75% fatality rate in humans.

So there are some cases in Australia where the horse owner died with the horse.

Pretty Horrific.

Pretty scary.

So there's some diseases.

It's not to scare you.

It's really to make you aware of what's out there.

And there are steps you can take to prevent their spread of these diseases.

Now, you can go online and search for vaccination schedules for

your equids, but here's pretty standard.

This is a pretty standard list right here.

So this one they break it down by the type of horse.

So, you have your performance horses.

Your horses that are traveling, going to horse shows.

So, that's the recommendation.

Then, you just have your pleasure horse or

your horse that you ride occasionally, or trail ride, stuff like that.

And then we have our broodmares.

Cuz broodmares have a specific special vaccination schedule, because

they need to build up that immunity to help pass it on to their foals.

So if you look down this list you can see tetanus is an annual vaccine or

if the animal gets injured.

So if you get a puncture wound,

something like that then you would give a booster to limit the spread of that.

So our encephalomyelitis is, that's an annual vaccine.

West Nile, depending on the West Nile vaccine you get.

But typically you give it once a year, maybe with the booster within the year.

It depends on the vaccine and you also want to give the vaccine prior to when

mosquitoes are really gonna start coming out in force, the spring or summer.

So our flu vaccine is a bi-annual, two times a year.

You can see horses that travel they give that every two to four months.

You can see the rhino the strangles is optional but you can give that annually.

Rabies annually.

We didn't cover Potomac Horse Fever.

But really in that region of the world, here in the United States,

where you would do that.

EPM again on that new vaccine.

And then you can see reading about foals.

So depending on the vaccine you're vaccinating for

is gonna dictate how often you give it and when.

But this covers just some of the ones that we've covered in this lecture.

All right, so that's the end of diseases.

Obviously, we can spend a lot of time on those,

and just wanted to briefly touch upon it.

Just remember, good bio-security, keep updated with your vaccines and

that will really help maintain your animals' health.

So in the final lecture of the health week, we're gonna kind of jump into some

of these genetic disorders and talk about how to prevent the spread of these.

So I'll see you then, okay?

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